Developers GREE, DeNA, Mixi, CyberAgent, Dwango and NHN Japan have announced they are removing a controversial monetization mechanic called “kompu gacha” from all their mobile-social games by the end of the month.

Kompu gacha (“complete gacha”) is akin to a virtual toy machine where players pay real world money to receive an in-game item at random. Players have the opportunity to win grand prizes, but only if they can acquire complete sets of specific items. Although an extremely lucrative income stream for Japanese developers, kompu gacha has drawn harsh critisism both for how close it is to real-world gambling and for the easy access children have to it. Over the weekend the mechanic was found to be in violation of Japanese law and a ban is widely anticipated.

Although the news will mainly affects Japanese developers, several western companies also make use of the mechanic in their Japanese mobile-social games. Zynga, for example includes kompu gacha in its Android role-playing game Montopia. For a more detailed explanation of kompu gacha and how its elimination will affect developers outside of Japan, read our feature investigation at our sister site Inside Mobile Apps.

Despite being available on Facebook for over a year without incident, Zynga has filed suit against French developer Kobojo, alleging the name of Kobojo’s game PyramidVille infringes on Zynga’s intellectual property rights.

Zynga has a history of pursuing legal action against developers who add “Ville” to their games’ titles, but what makes this case surprising is the delay. PyramidVille launched in January 2011, and Zynga filed suit on May 7, 2012. Zynga tells us it felt legal action was necessary after Kojobo refused to change PyramidVille’s name.

Zynga may also feel the need to sue now because of how rapidly Kobojo has managed to expand the PyramidVille brand. The game was a modest hit when it first launched on Facebook, but Kobojo has since gotten the game onto smartphones and into Arabic-speaking regions. Published via Peak Games,  مدينة الأهرامات (“City of the Pyramids”) is the No. 2 Arabic game on Facebook, currently boasting 2.4 million monthly active users and 470,000 daily active users. The localized version is very close to passing the peak numbers posted by the original English language version of PyramidVille, which saw 2.9 million MAU and 610,000 DAU in June of last year. Zynga doesn’t have an Arabic language presence on the Facebook canvas.

While expanding PyramidVille, Kobojo has also expanded its business, securing $7.5 million round of funding last year that the developer used to open new studios in Berlin and Madrid. Kobojo also told us at that time that it would push out a slew of new titles for Facebook and mobile during 2012, with some light investment in developing HTML5 games.

Zynga’s main obstacle is that it doesn’t hold the trademark for the word “Ville.” The company is currently trying to secure the trademark, but the process is still working through the U.S. Patent and Trademark Office. Zynga filed for a trademark of the phrase “With Friends” in 2011, with similar results.

Historically, trademark lawsuits over words or phrases in a name have been difficult to win. Case are typically settled out of court or languish for years after being filed. For example, Zenimax recently settled its suit against Minecraft developer Mojang, which claimed the upcoming title Scrolls infringed on the trademark of The Elder Scrolls games. Active Network sued Electronic Arts over the latter’s Wii game Active 2.0, but no results were ever announced afterwards. Tim Langdell of Edge Games was notorious for suing anyone who used the word “Edge” in a title, but this strategy eventually backfired and several of his trademarks were canceled in 2010 after he sued Electronic Arts over Mirror’s Edge.

We’ve reached out to Kobojo for a comment, but haven’t received a reply at the time of writing.

Zynga’s newest social game, Bubble Safari, targets the casual arcade genre recently cornered on Facebook by King.com with its hit game Bubble Witch Saga. The casual arcade shooter launches on Facebook and Zynga.com simultaneously tomorrow.

The bubble shooter genre predates Facebook by more than 25 years. The goal of these games is to match like-colored bubbles by firing a single bullet upward into a cluster of connected bubbles. A level is cleared when all rows, or a certain number of bubbles have been cleared. Like match-3 puzzle games such as Bejeweled, scoring bonuses are usually applied based on speed, matching bubbles in quick succession or by hitting special bonus items placed within the puzzle. These games have found a high degree of success on Facebook because users can learn and play the games quickly, and because they’re easy for developers to program and monetize. Like other Facebook-based arcade games, bubble shooters monetize through the sale of power-up items that increase scoring bonuses or through an energy mechanic that limits the number of sessions a user can play in a day.

King.com shot to the top three Facebook game developers by daily and monthly active users in the last six months on the strength of its bubble shooter, Bubble Witch Saga, which launched last September. That game was predated by King.com’s Bubble Saga, GameDuell’s Bubble Speed, wooga’s Bubble Island and several other variations on bubble shooters. Zynga hopes to make a splash with its bubble shooter by building on features that each of these games has introduced, adding a few of their own and introducing a new Flash engine that can run the game at 60 frames per second and produce high-gloss visual effects.

In Bubble Safari, players take the role of Bubbles, a wild monkey whose animal companions are kidnapped by poachers. Through a series of levels, Bubbles tracks the poachers and frees different animals from crates. The levels themselves are typical bubble shooters, with Bubbles himself manning the cannon at the bottom of a screen. As Bubbles matches color types in the puzzle, bubbles are cleared from the puzzle — but if bubbles are dislodged from the puzzle by clearing rows or clusters of connecting bubbles, these strays turn into fruit that fall toward the bottom of the screen and may land in one of three baskets just below Bubbles’ cannon stand, increasing the player’s score. The puzzle is completed when 10 of the bubbles in the the top-most row of the puzzle have been cleared, which converts all remaining bubbles to falling fruit. Each level requires a minimum score to progress to the next level.

As the player enters new regions on the world map, the challenges in the bubble shooter puzzles become increasingly difficult, with hazards blocking the user from making straight shots into the puzzle. For example, shooting beehives attached to bubbles will send a swarm of bees into Bubbles, causing him to random-fire the bubble cannon several times before the bees disperse. To overcome these challenges, players earn “Boost Bubble” items that that allow the user to complete the puzzle more easily — like a fire bubble that burns up any bubbles or hazards in its path. Players also earn animal helpers as they free animals from the poachers, such as humming birds, that bounce dropped fruit from the puzzle into one of the three baskets. The animal helpers level up as the player makes more matches and leave when the player fails to complete matches.

The use of Boost Bubbles and other scoring bonuses is where Bubble Safari becomes complex. Within a level, a player can only use a Boost Bubble once they’ve filled a boost meter by making successful color matches in succession. Filling the meter allows players to spin a prize wheel and whatever Boost Bubble it lands on is the one the player gets. Players can also increase their score by successfully dropping fruit into baskets. Three successful drops causes the level to catch fire, which indicates a score multiplier. Lastly, players have access to two extra normal bubbles in the form of friends that appear on a sidebar in the level, each representing a different color. By clicking a friend’s bubble, the player swaps whatever bubble they currently have in the cannon for the friends’ bubble — say, purple for red. On the other end of that exchange, the player will appear in their friend’s game representing whatever bubble they traded with (in this example, purple). A relationship meter increases the more friends use each other’s extra bubbles. When the meter is filled completely, the friend’s extra bubble can be converted to a Boost Bubble for one level. A powerup item allows players to bring in two extra friends so that all four possible bubble colors are available.

Aside from the bubble-swapping social feature, Zynga also plans to introduce an asynchronous two player competitive mode and weekly tournaments at some point after launch. Bubble Safari monetizes through the sale of powerups, energy refills and could potentially monetize tourney entry fees, though that remains to be seen. Interestingly, Zynga offers roughly half its power-ups for soft currency that can be earned through normal gameplay, while the rest can only be bought with premium currency purchased via Facebook Credits.

The similarities between Bubble Safari and other Facebook bubble shooters are obvious, while the differences are more subtle. For those not familiar with reigning bubble shooter Bubble Witch Saga, here are some key differences between it and Bubble Safari:

• Social features: Bubble Witch Saga enables friends to send currency, lives or “spell breaks” that allow players to progress to new areas on the map. This the extent of the social interaction between friends.
• Visual effects: Bubble Witch Saga is light on flashy visuals, like things catching fire.
• Adaptive gameplay: If a player repeatedly fails a level in Bubble Witch Saga, the puzzle will adjust to become easier. It does not appear that Bubble Safari’s puzzles will do the same — but this is something Zynga could introduce post-launch if players ask for it.*
• Monetization: Powerups (called “charms”) and life refill items in Bubble Witch Saga can only be bought with Facebook Credits. Special bubble types can be bought with soft currency. Zynga makes some powerups available for soft currency and allows players to earn Boost Bubble items through gameplay without spending soft currency.

It will be interesting to see if Bubble Safari picks up high-level Bubble Witch Saga players who have run out of things to do in King.com’s game. We’re also curious to see if Zynga’s simultaneous release on Zynga.com and Facebook reveals any value add to playing Bubble Safari on one platform instead of another.

Bubble Safari was developed by Zynga’s San Diego studio with some help on the Flash engine from a team in San Francisco. Senior Creative Director Mark Turmell — famous for his work on arcade games and franchises going all the way back to the Apple II and the Atari 2600 — oversaw the project, his first for Zynga and Zynga’s first arcade game.

“The industry has come full circle,” Turmell tells Inside Social Games. “The bubble genre’s been around for years — there’s something magical about match-3. The magic of that is maintained [in Bubble Safari], but with fire, the strategy, the map and presentation… this game innovates. And nobody’s going to out-Zynga Zynga at the cadence of new content. Coming [here] was like coming home.”

*ETA: As of launch, the puzzles in Bubble Safari will change if a user fails a level.

Electronic Arts’ social games lost nearly 3 million monthly active users and 1.2 million daily active users between Q3 and Q4 of FY 2012, but the company is hoping to bring in traffic by launching new social games over the fiscal next year.

The company’s earnings statement reveals it had 49 million MAU playing its social games, down from almost 52 million MAU at the start of the quarter. This number is up year-on-year from Q4 2011, though, when the company had 36 million MAU. EA had 10.7 million DAU at the beginning of the quarter but was down to 9.5 million by the end; this is lower than Q4 2011, which ended with 11.2 million DAU.

Revenue for EA’s digital segment (which includes social, mobile and digital downloads) showed continued growth for the third straight quarter in a row, increasing by 24 percent quarter-over-quarter to $87 million in Q4 2012. While Facebook game revenues weren’t broken out individually, CEO John Riccitiello did say during the Q&A portion of EA’s earnings call that the company’s social games are less profitable than its console titles.

Riccitiello also revealed during the investor call that EA plans to launch 41 games over the 2013 fiscal year across mobile, social and free-to-play platforms. President Peter Moore confirmed that Facebook will see new game releases from Sim City developer Maxis in Q1 2013 as well as one new game each from EA Playfish and EA PopCap. Details on these games were not given due to EA’s concern over being beaten to market by a clone.

EA’s social game business increased rapidly in summer and fall of last year after acquiring PopCap and launching The Sims Social. At one point in September 2011, the developer was No. 2 on AppData‘s social game developer leaderboard behind Zynga, with over 102 million MAU and DAU above 18 million. The Sims Social proved a tough act to follow, however, and EA’s subsequent social games — Risk: Factions, Lucky Gem Casino and Solitaire Blitz — haven’t seen nearly as strong a reception. The developer also recently revealed it will shut down Playfish’s classic Facebook Restaurant City next month. Currently, EA is the No. 4 Facebook game developer in both DAU and MAU behind Zynga, Wooga and King.com.

Beyond FY 2013, EA is planning to launch improvements and expansions on its monetization, retention and acquisition strategy. Playfish co-founder Kristian Segerstrale is currently working with a team of analysts on this project; EA says to expect announcements from him at an E3 investor breakfast next month.

King.com launches seventh “Saga” game on Facebook —  King.com is launching yet another game for its “Saga” series on Facebook, Pyramid Solitaire Saga, hot on the heels of Candy Crush Saga. The game follows aviator Helena Lightfoot as she explores the Pyramid Kingdom, clearing decks of cards and collecting scarabs along the way. Pyramid Solitaire Saga is launching with 60 levels.

Detroit using social game to help plan the city’s future — A new social game called Detroit 24-7 launches May 7 to let players decide on city planning priorities. Players are given different missions that award them with flags, which they then plant on a digital map of priorities like public transportation, affordable housing and environmental sustainability. The game is set to last for 21 days and developer Detroit Works will hold a city-wide meeting to let players and discussion participants meet so dialogue can continue.

Jay-Z launches Facebook game — Hip hop mogul Jay-Z just gamified his life on Facebook with a new title, Empire. The game covers the rapper’s early days Brooklyn’s Marcy Projects, with players working to acquire enough wealth and fame to escape.

Sulake launches new social hub for third-party games — Sulake is launching a new platform to expand its offerings to its Habbo Hotel players. The hub will feature content from third party game developers and signed U.K.-based Remode Studios as the first publishing partner. Remode Studios created iOS games like Magic Muddle and its first title for the new platform is expected to debut in July.

CyberAgent acquires Pitapat — Tokyo-based developer CyberAgent just acquired match-making service Pitapat. The service was originally launched by four university students as “Facematch” and lets users communicate with one another using social graphs and event functions on Facebook. CyberAgent is the company responsible for Facebook titles like Animal Land and Magic Saga, and it seems likely that Pitapat will be used to improve in-game communication.

Marvel: Avengers Alliance dresses up for The Avengers — Disney Playdom’s Marvel: Avengers Alliance made it onto our Top 25 Facebook Games list this week, but the game’s continuing to benefit from the film debut of The Avengers this week: special edition uniforms based on the characters from the movie. Any team using a character dressed in one of these outfits receives special abilities like follow-up and counter attacks in both the main game and player versus player matches.

NBCUniversal launches social game platform — NBCUniversal just launched a new platform for social and casual games called Universal Games Network. The platform will take all of NBCU’s various online, mobile and social games and put them on a single platform. Not only can players play games, consume media content and earn and redeem reward points, but they’ll also be able to go against their friends in tournament style games thanks to the integration of Facebook Connect.

I AM PLAYR hits 1 million MAU milestone — We R Interactive’s football game I AM PLAYR has passed the 1 million monthly active user mark and is now the largest Unity-powered game on Facebook. The game’s been growing steadily since it launched in October 2011, and its current traffic numbers also include over 120,000 daily active users.

Correction: It was reported that Remode developed My Star on iOS. This is not the case. My Star was developed by Mobile Pie.

Zynga’s off-Facebook games platform is still in its early days, but the growth is there and the games are running. Here’s how Zynga.com has evolved since entering open beta in March.

Traffic

Like most social games, the only place for traffic to go in the first six to eight weeks is up. Growth kicked in one week after the beta launch, starting from around 1.7 million MAU and 130,000 DAU likely left over from an internal beta test. In seven days, MAU grew 11 percent to 1.9 million while DAU went up 38 percent to 180,000. By the end of the month, Zynga.com was at 2.2 million MAU and 230,000. Now, at the beginning of April, it’s up to 2.8 million MAU and 420,000 DAU.

Here’s what’s interesting: Zynga’s DAU as a percentage of MAU (which is a measure of retention) also consistently rose during the first two months.

Normally, when a social game launches, we see MAU and DAU rise while the retention rate falls. During Zynga’s Q1 2012 earnings call, COO John Schappert explained that Zynga deliberately hasn’t driven users to Zynga.com via advertising or cross-promotion. This makes the platform’s growth seem even more significant, as it’s all organic, presumably from brand recognition or invites sent to Facebook friends.

Zynga tells us that advertising for Zynga.com will be turned on later in the quarter.

Game Features – Sidebar

The sidebar module appears on the right side of the screen everywhere on Zynga.com except when a game is in fullscreen mode. At the top of the module, players can click on their name to access their profile, list of recently played games (each of which display the number of pending game requests), their RewardVille point balance or the settings menu. They can also logout or toggle chat availability on or off. Also at the top of the module are two buttons that produce a chat window or a list of friends (called zFriends).

The rest of the module changes depending on where the user is on Zynga.com. On the homepage or profile page, users see a list of zFriends sorted into those currently online and those that have played Zynga games recently. This part of the module can be toggled to show a list of suggested zFriends — some of which are not on friends with the user on Facebook. In games, the user might see a horizontal list of users that have recently helped them in-game (with links to those users’ profiles) or a live feed of activity from other players of that game. The live feed can be sorted by everyone playing that game at the time or only zFriends that have played the game.

The sidebar is also a place where we’ve seen Zynga serve ads via Google AdSense, but this has only occurred when viewing the sidebar in a game that doesn’t make use of the live feed.

Games Features – Live Feed

Zynga’s live feed (sometimes called “social stream” or “zFeed”) is a feature that currently appears in the sidebar when playing CastleVille, CityVille and Hidden Chronicles. It posts in-game requests made by both zFriends and strangers, allowing players to click on any story to send and receive rewards. The live feed is important to the platform because the main value of playing a game on Zynga.com versus Facebook is that players progress faster if their game requests are answered synchronously instead of asynchronously. It’s also a means of meeting new friends that are more likely to help you in games so that users don’t have to spam their Facebook friends list, hoping some of them play the same games.

This is where Zynga.com has seen the most change in the last two months. At first, when there were fewer users on the platform, the live feed functioned much like the real time Ticker updates on Facebook. Users would click on a game story and receive the rewards attached to that story while also sending the poster the item they’d requested. As has always been the case with Zynga games, each story generated from a request only has a certain number of rewards attached to it — and once they’ve all been distributed, a player can no longer click on that story to receive or send items.

As it turns out, supply exceeded demand — more often than not, people were clicking on live feed stories and receiving a message that all the rewards had already been claimed. Manuel Bronstein and Reed Shaffner, Zynga.com’s general manager and lead product manager, tell us that the average user clicks on stories in the live feed 200 times per session (they declined to give session lengths — but assuming Zynga.com sessions are comparable to Facebook’s five to 20 minute range, that’s a lot).

The trick, Bronstein says, was not to change the supply side (which could unbalance the game), but to adjust demand using several different methods. The most obvious one was improving sharding of different user segments so that an optimal number of players populated a feed. Next, the developer tweaked refresh rates for different feeds, slowing down the rate at which stories appeared in the feed so that people weren’t just racing to click whatever was at the top. Lastly, the platform team introduced something called the Jolts system, which lasted barely a week as it was unpopular with users.

Here’s how Jolts worked for the brief time we had them: Players received a fixed number of Jolts in a given time period to spend on clicking live feed stories. Like an energy meter, it limited the number of times a player could interact with the live feed during a session. It also allowed players to “curate” stories from the feed, looking only for the rewards they actually wanted to have (e.g. currency instead of energy refills). When players ran out of Jolts, they could to wait for the Jolt meter to refill or could earn bonus Jolts by playing other Zynga.com games.

The last option that Bronstein and Shaffner are exploring is how best to communicate to the user that all the rewards have been claimed. Beyond that, they’re looking for a way to highlight the rewards that players do earn. Even if someone clicked 200 times and only got rewards half of the time — that’s still 100 free items. Platform terminology is something we expect to continuously evolve as Zynga looks for ways to explain platform features and systems to users.

There is also the question of how best to use live feed in games where it doesn’t apparently have a use. Currently, Zynga Poker and Words With Friends use the live feed space as an area to recommend new zFriends and possibly serve ads (see below). Bronstein and Shaffner say there is likely more that can be done for these games and others where request fulfillment doesn’t drive gameplay.

Game Features – Fast Load

The fast load feature is a button that appears on the site whenever a user exits a game. Clicking this button takes the user back into the game exactly where they left off without ever showing the user a loading screen. This is a very convenient feature that will likely gain more value as Zynga adds more features to the site that could potentially draw someone out of one game and into another or into a community event (e.g. a tournament or some other group activity). This is one Zynga.com-created feature that we could see Facebook adopting in the future if enough demand for quick-loading canvas apps emerges.

User Profiles

The Zynga.com user profile focuses on the way a person engages with games, displaying most-played games, recent games activity, zFriends on the platform and the number of friends the user has helped and the number of times they’ve helped friends in games for the week. In the past two months, the profile itself hasn’t gotten much of an update, although the sidebar on the profile page and the homepage now shows users which of their friends have played Zynga games recently.

Interestingly, the profile pictures displayed in this module indicate whether a friend is playing games on Zynga.com or on Facebook as all games on Zynga.com are synchronous with Facebook canvas. Facebook friends have a Facebook icon on the bottom of their profile picture while Zynga.com friends do not. Both players will receive an icon in the upper part of their profile picture indicating which platform game they’ve played most recently (no game icon seems to mean that user hasn’t played a Zynga game). Nowhere else on the site does Zynga.com differentiate between platform and Facebook players.

Lastly, the profile page is another venue where Zynga has explored serving display ads. So far, we’ve only encountered banner ads for furniture boutique One King’s Lane (which incidentally was co-founded by Alison Pincus, Zynga CEO Mark Pincus’s wife) on our profile page. These appear farther down the page beside the recent games activity feed, often requiring a user to scroll in order to see the entire ad.

The Potential

While Zynga declined to share session times or specific retention numbers, it seems as though engagement for Zynga.com games has the potential to be higher than what those games currently see on Facebook. Bronstein and Shaffner did share an emerging user behavior where players would log into Zynga.com to play a game — and then play the game again on Facebook later, picking up where they’d left off. Bronstein says Zynga owes this new behavior to the early decision the platform team made on keeping the game experience consistent and synchronous with Facebook canvas, right down to Credits as the sole payment method. Bronstein reports that monetization on the platform is “good,” but declined to elaborate.

The other thing that seems to be working is the synchronous nature of the platform. The counter that appears below Zynga’s logo on the lefthand side of the screen counts the number of users active on the platform concurrently — and refreshes every 60 seconds. That number has gone as high as 1.8 million during our own sessions; Zynga declined to give a specific number. The high demand for items out of the live feed also serves as proof of concept, even if there are some complications in managing demand.

Possible Pitfalls

At present, there are no features on the platform that prevent a user from playing games on Zynga.com as intended. The short-lived Jolts system, however, reveals that any sort of limitation on player activity will likely not work for Zynga.com. Synchronicity will also be an ongoing challenge for Zynga to manage on its platform, as it comes from an asynchronous background on Facebook and may not be prepared to manage demand across a broad range of systems.

There may be some issues in getting Facebook users to convert to Zynga.com players, on account of users having to approve a new set of permissions in order to use Zynga.com. The way the dialogue appears (see below) may also make less-informed users wary, as they may be confused by giving a company access to their data, versus a specific game.

What could really hinder Zynga.com’s growth down the line is discoverability. Facebook itself and many other games networks have struggled with the best way to help users find games, and no one solution has proved perfect. Bronstein says the platform team will consider everything from friend-recommended games and other types of social discovery to ratings systems or other means of sorting. Currently, with just five games on Zynga.com, it’s not a problem the developer has had much time to experiment with solving.

You can track Zynga.com’s progress with our AppData traffic monitoring service.

Japanese mobile social game network GREE has bought Funzio, the developer behind the popular mid-core mobile and social games Crime City, Kingdom Age and Modern War. According to a GREE spokesperson, the deal was worth $210 million.

As part of the deal Funzio’s CEO Ken Chiu and COO Anil Dharni will join GREE as senior vice presidents. Funzio’s CTO Ram Gudavalli and VP of engineering Andy Keidel will become vice presidents at GREE.

The acquisition is GREE’s biggest since April 2011, when the company bought OpenFeint for $104 million in order to bring its lucrative mobile social gaming network to North America.

Read the rest on our sister site, Inside Mobile Apps.

Both lists for May’s top 25 Facebook games saw two big debuts: The recently-launched Candy Crush Saga is already tearing its way up the charts while Marvel: Avengers Alliance just managed to break in thanks to some impressive user gains.

We start with the list of top 25 games by daily active users, which is the best way to evaluate a title’s core audience. Twelve games were up from last month, with the largest gain going to King.com’s Candy Crush Saga with 1.3 million DAU. Disney Playdom’s Marvel: Avengers Alliance has been steadily climbing the charts and had the second-highest gain of the month with 620,000 DAU. Rovio’s Angry Birds had the third-highest gain with 400,000 DAU. King.com’s Bubble Witch Saga didn’t quite make it into the No. 3 spot like we thought it might, but it still managed to gain 100,000 DAU and move into the No. 4 position.

CityVille and Hidden Chronicles had the largest losses on the list; CityVille was down by 1.4 million DAU, while Hidden Chronicles dropped 1.2 million DAU.

Now it’s time to check out monthly active users, which measures a game’s overall reach on Facebook. CityVille continues to hold the No. 1 spot on the list, with slightly more than 4 million MAU over Texas HoldEm Poker in the No. 2 position. Zynga’s Hidden Chronicles had the largest drop this month, down by 4.7 million MAU, and subsequently dropped from the No. 3 spot to No. 5.

The largest gain belonged to Zynga Slingo with 4.3 million MAU, followed closely by Angry Birds with 4.1 million MAU. Bubble Witch Saga continues to grow, taking third place for gains this month with 2.9 million MAU. Although it debuted on our Top 25 list in the No. 25 spot, Disney Playdom’s Marvel: Avengers Alliance had the fourth-highest gain of the month with 2.1 million MAU.

All data in this post comes from our traffic tracking service, AppData. Stay tuned next week for the beginning of May’s  Top 25 gainers and losers, when we look at the continued performance of games that appeared on the top 25 DAU list.

Zynga takes the first step in promoting games published through its partner programs today by adding Row Sham Bow’s Woodland Heroes to the Facebook cross-promotion bar that appears above Zynga games.

Adding a game to the zBar, as Zynga called the tool, seems like a small thing compared to what Zynga wants to accomplish in publishing third party games on Zynga.com. Cross-promotion bars have been thoroughly explored by 6waves, Applifier and Tapjoy (which acquired AppStrip) on both social and mobile — and 6waves has a sizable head start on Facebook games publishing. But Zynga has two features that other cross-promotion networks lack: brand recognition and size (65 million daily active users and 292 million monthly active users on both social and mobile as of Q1 2012). Both of those are key factors driving interest from smaller developers in the Zynga publishing platform.

As detailed on Zynga’s blog today, publishing partner head Rob Dyer says that Zynga intends to drive traffic and test promotions during this early beta phase to see what impact it has on Zynga’s network as a whole — and what impact Zynga’s network will have on an individual game.

“Driving players to try out new social games is one thing, but the trick is making sure they stick around,” Dyer’s post reads. “That’s where some of our upcoming tools to increase social engagement come in.”

The Zynga partner program is still a mystery to outsiders. We do know that the revenue share between publisher and developer is the traditional 30/70 percent split — after Facebook takes its 30 percent cut of Credits transactions. We also know that of the companies Zynga has announced so far — Row Sham Bow, Mob Science, Sava Transmedia, Konami, Rebellion and Playdemic — two have long term experience with the Facebook platform and two do not currently have any Facebook games announced.

Here’s what we don’t know: Will the publishing platform create sustainable games on Facebook and mobile, or will it serve as a hunting ground for Zynga’s next acquisition prospects? We can infer from Dyer’s blog post that Zynga will take a hands-on approach to helping publishing partners refine their games, not unlike what RockYou once did for Playdemic. We’re also reasonably sure Zynga will extend its publishing operations to mobile at some point in the future — but it’s unclear if that will operate through a mobile version of its Zynga.com platform.

Woodland Heroes is Intersouth Partners-backed Row Sham Bow’s first Facebook game. It launched in October 2011 and peaked at 190,000 monthly active users and 20,000 daily active users in that same month, according to our AppData traffic tracking service.

Restaurant City will be taken offline from both Facebook and the App Store on June 29, according to a Wall Photo added to the game’s album today. Players are being encouraged to move to The Sims Social both with a virtual currency bonus and the ability to convert existing Restaurant City premium currency to Sims Social premium currency.

Playfish’s Restaurant City was one of the top restaurant simulation games on Facebook in 2009; it maintained that momentum through 2010 after EA acquired the developer. The game recently marked its third birthday on Facebook in April — having shrunk by more than 90% in size from its peak numbers of 5.2 million daily active users and 18 million monthly active users to today’s 310,000 DAU and 1.8 million MAU, according to our AppData traffic tracking service. The real problem seemed to come for the game around September 2011 when retention (which we can measure by taking DAU as a percentage of MAU) dropped below 20 percent. Restaurant City rallied in October around the time its iOS version, Restaurant City: Gourmet Edition, received a major update — but retention dropped again in early 2012 and Gourmet Edition fell off the top apps lists.

As a genre, restaurant sims still show some growth on Facebook and mobile when they first launch. The games lack staying power, however — we still see Restaurant City as the second-largest game in the category on Facebook after Zynga’s Café World, which is also in decline.

As a company, EA is apparently struggling to maintain its position as a top developer in social and mobile. It’s slipped to the No. 4 position of top developers on Facebook by DAU and wooga is about to overtake it for the No. 2 position on MAU. On mobile, the developer pulled two titles from the App Store for poor performance in as many months this year. EA has also lost a lot of its staff to Zynga in the last 12 months and is now rumored to be facing layoffs, though the company has denied it. EA reports its Q1 2012 results next week.