Social sports applications are some of the oldest and most literally “social” games on Facebook: Users compete with friends to do things like create fantasy sports leagues or pick winners for tournaments like the March Madness college basketball championships happening now. These apps can also be a more powerful way for more traditional sports companies to reach Facebook users.

And so, Yahoo is buying Citizen Sports, one of the leading social sports developers on Facebook, for an undisclosed amount. In the announcement press release, Yahoo describes how the company will fit in with its destination site, Yahoo Sports:

Yahoo! Sports’ content will be integrated into [Citizen Sports' products], creating a seamless experience for sports fans wherever they are. On Yahoo! Sports, users will be able to broadcast their allegiances, create or join a conversation with friends and fans and cheer for their teams through Citizen Sports’ applications.

Citizen Sports currently has 719 applications (many for specific teams) on Facebook, according to our independent measurement service, AppData, for a total of 1.51 million monthly active users and 156,000 daily active users. It appears to have an early lead over rivals CBS and Watercooler, in terms of traffic to its March Madness bracket app. Yahoo Sports had 39 million monthly unique users in the US last month, according comScore — funneling these users into Citizen Sports’ apps will lead to more traffic on Facebook.

AllThingsD, which broke the story yesterday, reports that the startup raised $10 million from Kleiner Perkins Caufield & Byers partners Kevin Compton and Doug Mackenzie, through a separate investment vehicle, Radar Ventures. It used to be known as ProTrade, the virtual sports stock market, before it changed its name and product line and started building social apps a couple years ago.

If you were to go up to a gamer — an older one, at least — and ask them what the best fighting game ever made was, they would probably tell you Street Fighter II. The title has been one of the most popular and well balanced fighting games for decades and certainly one of the most famous arcade games to date. If you don’t believe that, just look at how many versions exist. Nevertheless, last week gave birth to the anticipated release of Street Fighter IV on the iPhone.

Developed by Capcom, it is certainly one the top five biggest ports to the device, joining a list containing such titles like PopCap’s Plants vs. Zombies or Electronic Arts’ Rock Band. However, currently priced at $9.99 in the App Store, one has to wonder if the price matches the hype.

Currently, the game offers eight playable characters from the classic franchise, including Ryu, Ken, Chun-Li, Blanka, Dhalsim, Guile, M. Bison, and Abel. It is a bit disappointing to only see a fraction of the characters from the series – though the most important ones are there – but considering that the game is a fraction of the price of the console version of Street Fighter IV, it’s understandable.

When players start up the game, they are presented with three modes, Tournament, Dojo, and, of course, multiplayer. Likely, however, users will start with the tournament mode as the majority of these players are probably Street Fighter fans already, and don‘t need training — and probably don’t have another person with an iPhone readily available.

This mode is essentially the “Story Mode,” from previous Street Fighters, sans the actually story. It still follows the same progression curve as far as game play goes, though. Users battle computer controlled characters one by one with ever increasing difficulty. The abilities are more or less the same as any other Street Fighter title, so it isn’t terribly hard for a veteran of the game, once you get used to the controls (more on that a bit later).

What really makes the game different is the new Dojo mode, which has been described on numerous occasions as “Street Fighter boot camp.” Consider this a challenge/tutorial mode. Players will be given increasingly advanced win conditions and a time limit in which to complete them. For example, one challenge will focus on combos, asking the player to do X attack followed by Y attack, with increasing complexity for each successive challenge. Another might teach the elements of using special attacks, you know, Haiduken, by blocking all damage done by normal attacks.

Regardless of the lesson, each completed challenge will be ranked either S, A, B, or C. In order to proceed to the next level, at least a C is required. Nonetheless, for those that enjoy things like achievements, a lot of longevity will be garnered out of the Dojo, for S ranks are actually extremely difficult to get, and there are a ton of different challenges. But then again, we were never Street Fighter arcade champions either.

As interesting as Dojo mode is, the real glory comes from the multiplayer. Obviously this isn’t your Facebook-style asynchronous multiplayer, and it is certainly not for the weak. Using Bluetooth, players can sync up and fight each other in some classic arcade mayhem. Surprisingly, with the right people, it’s about as much fun as any console or arcade version.

There is one annoyance to get used to though. The controls. Capcom does the best it can, but it really just comes down to placing the classic arcade joystick and its four buttons on the touch screen. As has been stated in past reviews, this just doesn’t work as well on the iPhone because there is no tactile feedback, and any serious game player can tell you that they feel where their fingers are, not see. Unfortunately, for a fighting game of this caliber, there isn’t really a viable alternative to the control scheme. Once you do get used to it, however, it’s not so bad; though it is frustrating to lose because you had to look to see where your thumb was for a split second.

Luckily , there is one saving grace to the controls. Capcom is certainly aware of the lack of tactile feedback, and does its best to mitigate the issue, allowing players to customize their controls. You can actually drag them anywhere you want until you’re comfortable (a great thing for lefties), change their transparency, and actually change the overall size! That last one, is certainly a godsend for those people with big fingers.

If you have an iPhone or an iPod Touch, and you’re a fan of Street Fighter, this is a game for you. Though it doesn’t have everything that the console rendition of Street Fighter IV has, it is still an excellent port, and has plenty of the nostalgic elements – from fighter specific levels to familiar taunts – for long time players. Granted, the controls take some series getting used to, and for most, it’s going to probably hit or miss. Nevertheless, once you get the hang of it and get into some multiplayer action, this application will become $10 well spent.

Playfish has been quiet in recent months, but it’s now working on a new title called Hotel City. The game is live, but in the early beta stages, so we’ll be saving a full review for later. Here’s what we see, now.

The game is a cross between Restaurant City and the Chinese title, Happy Hotel. That said, the emphasis will most likely be on the former, as the Restaurant City elements will probably pertain to the concept of streets full of hotels, hiring friends, and decorating isometric interiors. In regards to Happy Hotel similarities, it likely includes the concept of increasing the value of rooms through decor and letting your non-employee friends (as well as non-player characters) check in and pay you fees to stay.

Happy Hotel has a bit more to its guest recruitment than just this. There’s a whole spiel about recruiting better paying guests, critics, and celebrities to increase your hotel’s rating and popularity. Playfish could incorporate something similar, but the company has, in the past, always tried to be more original with its concepts, than others. Expect features that are similar, in essence, to other Facebook hotel games but done in a much more different way. Nevertheless, in the end, all we know for sure is that the game will grant “more customization offers than ever before” and that you “will employ some of your friends,” with the goal of becoming a 5-Star hotel.

On a different note, it is somewhat surprising that Playfish is not taking the city-building route — especially because its parent company, Electronic Arts, owns the formative Sim City franchise. Already we have seen a number of city games from small developers as well as NanoTowns from Digital Chocolate and Social City from Playdom. Meanwhile, other competitor, CrowdStar is going with tycoon games, having released Zoo Paradise.

Still, while the SimCity-esque games seem to be the bigger boom at the moment, Zynga has also trademarked the names HotelVille and Hotel World, so we could be seeing more hotel games soon.

Last week it was number two; the week before that it was nothing, because it had just been released. Social City, the new city building game from Playdom, has flown to the top of our weekly AppData list of top Facebook gainers by daily active users, adding more new players than games several times its size.

There’s obviously some heavy advertising from Playdom behind the scenes. But as we found when it was brand-new, Social City is actually a great game. Nevermind that players have experienced technical problems since the game’s launch; they keep coming back anyway.

Proof is in the numbers. We’ve been watching Social City’s DAU as a percentage of monthly active users — the number of people among all the players who return daily — for several days. Following the launch-time spike of new DAU, Social City’s percentage settled to its current 44 percent. Defying our expectations, it hasn’t dipped any further. It’s an extremely high number that seems to show Social City’s new players genuinely love the game.

Nevertheless, Playdom still has to fight it out with other publishers to rule the emerging city building genre. At lower positions below, you can see two similar games, Towner and My City Life:

	Name	DAU	Gain	Gain, %
1.	Social City	2,475,502	+1,732,288	+69.98
2.	Birthday Cards	2,636,459	+1,333,714	+50.59
3.	FarmVille	30,973,370	+1,060,995	+3.43
4.	Café World	8,896,906	+366,051	+4.11
5.	Texas HoldEm Poker	6,637,643	+332,075	+5.00
6.	Mafia Wars	6,552,404	+201,596	+3.08
7.	Tiki Resort	590,285	+192,160	+32.55
8.	Pet Society	4,456,973	+152,818	+3.43
9.	Bubble Island	580,362	+150,714	+25.97
10.	MindJolt Games	3,329,168	+144,263	+4.33
11.	Bejeweled Blitz	2,798,882	+87,439	+3.12
12.	Towner	189,978	+77,490	+40.79
13.	Mahjongg Dimensions	228,713	+63,324	+27.69
14.	2010 Bracket Challenge	54,335	+49,459	+91.03
15.	PoxNora	46,975	+46,507	+99.00
16.	Country Life	2,577,705	+46,329	+1.80
17.	My City Life	532,022	+38,604	+7.26
18.	Games	279,840	+38,579	+13.79
19.	Bola	87,397	+37,532	+42.94
20.	SPP Ranch!	200,026	+34,773	+17.38

Following Birthday Cards, which is only loosely a game, there’s a foursome of Zynga games: FarmVille, Café World, Texas HoldEm Poker and Mafia Wars. All said, Zynga has managed to add about a million DAU since last month, edging over 67 million this week.

Tiki Resort returns us to Playdom. This island resort building game was released a couple weeks before Social City, but it only has about half the players and far fewer DAU. Still, if you’re not measuring it against its sibling’s stand out growth, Tiki Resort is doing pretty well.

One special circumstance to note this week: every one of the top 10 games on the list is from a large or well-funded company. That’s not the case every week, but it may happen more often as the big boys acquire ever more leverage to promote their products.

Although Playdom chairman Rick Thompson is personally investing in other social gaming startups, the company itself has just put $5 million into Argentina-based developer MetroGames. The investment is an unusual move for a social gaming company; acquisitions have been the norm.

Although MetroGames has popped up from time to time on our weekly gainers lists, it has stayed pretty quiet — although its new city-building game, Towner, is growing fast. We currently count 8 of its games on AppData, our independent traffic analysis service for Facebook apps. The company says it currently has more than 30 total between Facebook and the web. Playdom chief executive John Pleasants will join its board.

More, from Damian Harburguer in the press release:

We are very confident MetroGames will become one of the world leaders in social gaming during this next wave of explosive growth in the industry. We already have more than 30 games online across Facebook and our own social gaming platform and many more to be released during 2010. We are pleased Playdom has recognized our potential and chosen to invest in us.

The press release says that this money is just part of its first venture round of funding, so the company may have raised more, or could be looking to do so.

Playdom is one of the largest social game developers, with strong presences on Facebook and MySpace. It raised $43 million on a $260 million pre-money valuation last fall and bought social app developer Green Patch and iPhone developer Trippert Labs; it most recently bought OffBeat Creations, earlier this month. Its latest game, Social City, is currently taking our charts by storm.

Gambling card games are easily one of the oldest forms of social games on Facebook, or on the internet in general. They’re easy to make, not very complex, and many people who would be interested in the first place already know the rules. It’s no wonder that Zynga’s TexasHold’Em Poker (now Zynga Poker) was one of the top social games for so long.

However, Zynga Poker is a bit dated and not everyone likes to play synchronously against others (especially when they are learning how to play), and so, the social developer has released Poker Blitz, a Facebook game that adds a little bit of that Las Vegas flare to an old genre.

We took a quick look when we spotted it live last night. Now, here’s our full review.

There are two key difference between Poker Blitz and the older title: The game doesn’t have all human players sitting around a table; and, it isn’t quite the same game format as the many Hold’Em games circulating various social networks. Essentially, players get two cards and the House gets two cards. If you make a bet, you get five more, and if you like the hand you have, make a second (or fold if your cards are bad). After the second bet, the game announces who won, the player or the House, and its on to the next hand.

Each round consists of 60 seconds to earn as many chips as possible; hence the name “Blitz.” However, it is all done so in this highly satirized collection of levels that represent Las Vegas, Jersey Beach, and even, well, Antarctica. Each level, however, is gated based on the user’s level, so the more you play, the more stages become available.

Of course, unlocking new places to play is for more than just aesthetics, as each stage has its own set of rules. For example, in the earlier areas, players have a tutorial help element that displays the percent chance to win and what sort of hand they hold, while later ones do not. In addition to less hand holding, the later, unlocked stages, also tend to have higher stakes per hand, and a few even remove cards from the deck.

As one can imagine, it gets very difficult to play at these later points, and thus harder to earn chips. Currently, however, the individual earning of chips doesn’t seem to mean much. You get to customize an avatar (and eventually a house, that is “coming soon”), but none of it costs anything yet. Nonetheless, your earnings do count towards your Team’s total value.

In addition to leaderboards made up of Facebook friends that play, there’s a weekly challenge. By adding people to your team, the game tallies how many chips everyone has cummulatively. Unfortunately, it’s not 100% clear what the challenge is — the game has been out less than a week — but the current challenge appears to be reaching a tally of 1 million chips, between all your teammates. Certainly, this is a daunting challenge, as you can only bet up to 500 chips at a time at the ealier levels (higher level stages allow for bigger bets, though we haven’t unlocked them yet).

Of course, there wouldn’t be much incentive if it was just a random number. Teams that reach the 1 million mark will become eligible to win an iPod Touch, but they only have five more days to do so after winning. Of course, this number becomes increasingly difficult to attain as players can only play so many rounds until they are out of “tokens” – which basically acts like energy in Mafia Wars - and have to wait an hour or so for them to recharge.

That’s okay though, because the game actually does have some good ways to make the most out of the rounds you have available. Poker Blitz actually incorporates two unorthodox elements to poker games. These are the “Mystery Box” and the concept of power-ups. The former is basically something that you win during play that could contain thousands of chips, or a random power-up. Now don’t think that one is better than the other, because the latter can completely change the tide of a hand, granting players the ability to make their hand “luckier,” swap cards with the house, double the pot, or even view one card in the House’s hand.

Honestly, though, the last power-up doesn’t seem all that useful, because it gives you no real gist of what they hold. That said, there are a number of things one can’t do in games like this. Poker is a strategy game of knowing when to fold, when to bluff, and when and how much to bet. Obviously, you can’t do all of this (especially forms of bluffing) on a game like this where you’re facing computer opponents. To that end, Zynga Poker still seems like the better choice of apps.

Nonetheless, Poker Blitz is still fun, for what it is, and is something a non-poker player would probably love. To that end, there is nothing wrong with gameplay, but there is a bit of a complaint in starting the game up. In fact, this is a complaint for most new social games lately: First of all, Poker Blitz requires you to let them email you with offers and updates in order to play. [Update: Apps can require email sign-ups, but Facebook won't provide emails except through the API. In this case, Zynga directs users through the Facebook API once they click on its interface.] Normally if a player wants updates or offers, they will go to the game and click the offers button. Frankly, this is just a recipe for unwanted spam. That isn’t to say Zynga will do this, but if all Facebook games start making this requirement…. Well, you get the picture.

The other issue, is it feels like a lot of social games are taking advantage of the fact that most Facebook users are not “gamers.” At the top of the last half a dozen games reviewed, there is a nifty little “setup progress” bar. This bar, has nothing to do with being able to play a game, but only consists of steps such as allowing emails, becoming a fan, bookmarking, allowing automatic feed posts (sometimes), and giving a 5-Star review. The reason for doing this is understandable, but always asking players for a 5-Star review defeats the purpose of “reviews,” doesn’t it?

That aside, Poker Blitz is still a wonderful little card game app that most non-poker players will probably enjoy. Considering the level of cross-promotion Zynga games get and the millions of players on its other titles, this is a game that will probably grow very quickly. Whether or not it will get up there with other titles from the developer is yet to be determined, but expect to see Poker Blitz’s AppData page rise in some of our Top 20 charts in the near future.

Most of our readers gladly take the time to look when big developers like Playdom, Zynga, Playfish (Electronic Arts) and CrowdStar launch new games in a popular genre. But sometimes smaller late-comers do a great job out-innovating the big guys — here’s a look at two thematically contrasting titles.

The first game is World at War, a modern warfare-style take on the classic mafia role playing game. That said, the game has all the standards: Money, missions, energy to complete the missions, stamina to battle other players (dubbed “ammo”), and so on.

Really, it’s the style that’s most interesting. Everything is based on modern military technology, with the goal being to build up the largest military force in the world. Of course, to do so, users must complete missions in order to level up, unlock more powerful weapons of war, and use the money earned to build up their forces of land, sea, and air.

This actually is where World at War stands out a bit: when you choose your country, you don’t get bonuses such as “faster energy regeneration” or “faster health regeneration.” On the contrary, the perks go towards branches of your military. As an example, if you choose the United States, your air force is stronger than others. If you are the United Kingdom, your navy is stronger. This obviously plays a fairly significant role in choosing what units to build when.

As far as the units themselves go, these are more or less the equivalent of items in something like Mafia Wars. They add attack and defense stats to your profile, and are required for certain missions, and in the end, a squad of riflemen is still, essentially, the same thing as an uzi or what-not in another RPGs (though it is a bit more gratifying to have little minions rather than just a gun).

Additionally, players can also build up a base to earn periodic income, but what is different is that the user can convert outdated structures to new ones as they increase their level and unlock new buildings. In many other RPGs, you are forced to buy more land (which you can still do here). Furthermore, each building can be upgraded up to three times to improve efficiency, and some of them even grant bonuses to health, defense, attack, and so on.

Okay, granted, World at War isn’t wholly original, but then again, most Facebook RPGs aren’t. Do missions, level up, buy new stuff, invite friends to become stronger, and take over the world – in theory. That’s about every social RPG in a nutshell. However, if you like modern military technology, and you’re sick of mafias and gangsters, then this is an app worth checking out. Moreover, with over 1.1 million monthly active users, you certainly won’t be alone.

The next app is the exact opposite to World at War, in that it is about peace. Called Ocean World, much of the game’s user based appears to speak Chinese, judging from its page; the developer is little-known Stand Up Network. The app has around 255,000 monthly active users.

Ocean World is your standard virtual aquarium game. It is a bit behind the times, as that boom appeared to peak last fall, but the game is still a decent rendition of this common genre. The basics are all present: buy fish, feed fish, plant decorations, and make the world a happier place.

One thing that makes the game stand out, however, is the overall atmosphere that comes with it. The visuals are a cross between Zynga’s somewhat cartoonish FishVille and Tall Tree Games’ more realistic looking Fish World. It actually looks quite good, and there isn’t a bad selection of decorations to choose from either.

What makes Ocean World more interesting is that players are in the ocean, not a tank. That means all of the visuals are centered around reefs, beautiful shells, and actual sunken ships. There are still fun, random, items tailored to special holidays. At the moment, these are decorations themed for St. Patrick’s Day and the Chinese New Year. Unfortunately, these all cost the virtual currency, Sun Coins, or an exorbitant amount of the in-game Shell Coins.

Further adding to the atmosphere, the fish actually grow and change as they reach adulthood, rather than just get bigger. Of course, you sell them when this cycle completes (“release them”), and then buy some more. Standard aquarium game economics. As players continue to repeat this process of buying, feeding, and releasing, they earn new levels and, in turn, unlock new fish and decorations to purchase.

The music helps pull the game together, too. It’s not some bouncing rhythm like so many other virtual aquarium titles have, but rather it’s a very tranquil tune that fits with the mysteries of the ocean. Frankly, with the opening directions of the game talking about saving the sea, it sounds like something you might actually hear at a place like Sea World.

In the end, neither World at War nor Ocean World bring anything significantly new to the realm of social games — but they show that smaller developers can take a tired genre and make it interesting, even when the big developers are using their resources to get the most users.

If there is one type of game that seems to circulate more often than any other around the web and mobile devices, it’s tower defense. For the most part, these games are a dime a dozen, but every once and a while, a developer does something interesting with this tired genre. This time, it is a quirky, $0.99, iPhone app called Tweet Defense from the Promethium Marketing Group and GrinLock Limited.

As far as tower defense games go, Tweet Defense is still fairly standard. Players choose from 10 different maps and construct various towers to try to take down enemies before they get from Point A to Point B. As expected, towers vary in strength, abilities, and cost: Some are cheap with high rates of fire, some do area of effect, some are short range, but powerful, and others boost whatever defenses you have currently up. However, each tower has a unique, garage-built look that adds a bit of flare to this basic gameplay.

Conversely, the enemies, in this case, zombies, come in their own odd shapes and forms. This includes the basic Sneakie zombie that attacks in hordes, the hard to kill, and overweight Blubberbie zombie, and borderline uncouth Mombie that spits out two baby zombies (called Zuppies) when she dies. Unfortunately, there are only five types of zombies, but with a zany, cartoon style, they are all amusing to watch.

Beyond visual style, Tweet Defense also increases the difficulty of the game through the maps themselves. Most of the time, these types of games have a set path that the player can easily see, with towers placed around it. In this app, harder maps have no such luxury, and towers can be placed anywhere. Normally, this might not mean anything, but in Tweet Defense, should a tower be in a zombies way, they’ll just plow right through, destroying it in the process.

Quickly, the app becomes a game of strategic placement and money management. In regards to the latter, it works like virtually any other tower defense title. Towers can be upgraded or scrapped, and money is earned for each enemy slain. And don’t think upgrades are optional, as even though the game starts off easy, things can quickly get out of hand and the player even more quickly overrun.

With all this talk of the game design itself, it is easy to forget the main gimmick of Tweet Defense. Per its title, the game is actually connected directly to Twitter. No, this isn’t about tweeting achievements, but rather, a user’s social activity on the network itself, influencing gameplay. Once a user logs into their Twitter account, Tweet Defense actually picks up on your friends, followers, and the number of tweets you have made in order to grant users significant bonuses in the game.

To break it down, the more friends you have, the faster rate of fire your towers get. More followers will give you greater range. And the total number of tweets increases damage. In addition to this, there is a daily Booster that will grant random bonuses such as cheaper towers.

As unique as this use of Twitter is, Tweet Defense also incorporates the social platform OpenFeint to improve longevity with standard leaderboard rankings, and a fairly sizable list of achievements for players to earn and boast about.

Without a doubt, this iPhone app has one of the most curious and unique social integrations we have seen to date. Moreover, the game is actually fun and more than just a gimmick. Could Tweet Defense do more as a tower defense title as a whole? Absolutely. Even a little more variety in the zombies would by prudent in improving overall quality; especially considering the game’s visual style. Nonetheless, this is an app that show that, in game design, just looking at something in a different way can lead to more creativity.

Zynga has been pretty quiet over the past few months. The last game the company launched was PetVille, back in early December, and it has recently allowed some of its less successful titles to shed users, focusing in on a handful of big hits. This emerging strategy makes the release of Poker Blitz, a new casino game, all the more significant.

Poker Blitz follows in the footsteps of Zynga’s first-ever hit, Texas HoldEm Poker. Today, Texas HoldEm is Zynga’s third-biggest game, with 28 million monthly active users — that makes it Facebook’s seventh-largest app overall.

But there’s one problem with Texas HoldEm: it’s a skill game that requires deep expertise and strategy to master. Even playing a few casual hands requires more knowledge than, say, planting your first seeds in FarmVille. Texas Hold’em has a devoted following of many millions worldwide, but Zynga’s version, HoldEm, is ultimately unlikely to break out — especially as expert players graduate on to playing for real money.

The solution in Poker Blitz is cutting down on the skill gaming elements to make Hold’em more welcoming to inexperienced and casual players. Let’s take a quick tour of the game.

Graphically, Blitz has much in common with Zynga’s YoVille, from the initial setup of an avatar to play with to the dealers and casinos. Building up a character need only take a few moments, and then you’re on to the tutorial.

Next, Zynga hits players with a forced email subscription screen. This is a calculated violation of Facebook’s latest developer rules, which insist on giving users the ability to opt out [Update: This is not clearly a violation, but it's also not clearly in compliance. More here.]. The game isn’t fully released yet, though; this feature will likely disappear soon.

As in Hold’em, you’re dealt two cards, while five more are laid out on the table. But the differences begin there. As most hands are dealt, you’ll have the option to swap your cards if you don’t like them. You can also fold without betting. Some rounds will offer the option of flipping over one of your opponent’s cards, others a “four leaf clover” special power that gives you a “luckier” hand.

Unlike Hold’em, there are no rounds of betting before the fourth and fifth cards are laid out on the table. And at lower levels of Blitz, you’ll get to see the likelihood that your hand will win the match. All told, the odds are heavily stacked against the dealer. You’re also playing one on one instead of against a table of other players — though there’s a “team” element of the game that’s yet to be released.

As you win hands, you’ll unlock mystery crates that hold prizes. Each round of play is timed at 60 seconds, though winning a hand will add to the timer.

Perhaps most importantly, there’s a limit to how many rounds can be played each hour, along with special tokens that only appear every few hours. At the moment, there’s nothing players can do to buy more time, but Zynga obviously has the option of letting people pay for or earn more time. There are also inventories and a virtual home that are only marked “Coming Soon”.

All of Zynga’s changes make Blitz more of a video game than a casino game like Texas Hold’em. In recent years, as Hold’em players have gained notoriety through massive tournaments held on ESPN and other channels, they’ve replaced the seedy image of gamblers with one of glamor and excitement. Blitz is an attempt to give players the powers and high lifestyle of a pro player without doing any of the work to get there.

Meanwhile, players who do want to take Blitz to the next level will doubtless be nudged on over to Texas HoldEm, with its more serious atmosphere and standard rules of play. This two-for-one strategy isn’t just canny; it’s the latest way to promote games, since Facebook tightened up its viral distribution rules.

We’ll keep an eye on Blitz as it grows, and review the game again once Zynga unlocks some of the special features mentioned above.

Playdom’s new city building game, Social City, is on fire. It tops out this week’s AppData list of fastest-gaining Facebook games by monthly active users with 4.5 million new users, more than four times as many as the next-closest game.

The company has spared no expensive in promoting Social City — we’ve been spotting its ads repeatedly on Facebook. Despite being dogged by errors since its release earlier this month, the game is also attracting an incredibly loyal fan base. Our stats currently show that some 44 percent of its monthly users also return daily, although that’s admittedly an early measurement that will almost certainly drop a bit over time.

Although not terribly different in mechanics from other time-management games, it’s starting to look like SimCity-style games could be the next boom in Facebook gaming. We first pointed out the trend before Social City’s launch, when a handful of independent companies launched their own games. My Town, My City Life and Towner are still doing pretty well — you can see two below, while My City Life came in at number 21 — although it remains to be seen how they’ll hold up under the assault of a big company like Playdom.

Here’s the rest of the list:

	Name	MAU	Gain	Gain, %
1.	Social City	4,903,377	+4,583,083	+93.47
2.	Tiki Resort	2,412,391	+1,063,186	+44.07
3.	Bubble Island	2,245,579	+1,038,735	+46.26
4.	MindJolt Games	20,921,341	+995,553	+4.76
5.	Jeux Gratuits	1,000,142	+757,906	+75.78
6.	Texas HoldEm Poker	28,026,262	+746,189	+2.66
7.	Zoo Paradise	656,381	+544,053	+82.89
8.	Towner	981,779	+534,449	+54.44
9.	Restaurant City	15,407,398	+467,571	+3.03
10.	Mahjongg Dimensions	1,005,516	+394,272	+39.21
11.	Ameba Pico	346,812	+322,334	+92.94
12.	Ninja Saga	4,293,040	+307,537	+7.16
13.	Music Pets	612,719	+297,674	+48.58
14.	SPP Ranch!	2,901,793	+296,043	+10.20
15.	Top Stalkers	560,276	+292,579	+52.22
16.	Jumping Dog	800,306	+263,994	+32.99
17.	Puzzle Bobble	561,610	+243,235	+43.31
18.	My Town	3,594,385	+242,052	+6.73
19.	Glamble	592,164	+231,397	+39.08
20.	MMA Pro Fighter	788,926	+231,223	+29.31

Tiki Resort is also a Playdom game. It and Bubble Island, by Wooga, were both leaders on last week’s list, too. Despite the apparent thematic similarity, they’re totally different: Tiki Resort has players build an island amusement park, while Bubble Island is a well-made bubble blasting game.

MindJolt Games, at number four, is continuing the growth trend it started when a group of former MySpace execs acquired the company. It’s followed by Jeux Gratuits, a French-language app that, like MindJolt, is a wrapper for a multiple casual games.

Zoo Paradise is the last game we’ll point out. The recent release from CrowdStar attempts to follow up on the smashing success of RockYou’s Zoo World. But so far it hasn’t had time to budge the needle for CrowdStar, which actually dipped below 50 million MAU this week.