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players can also build up a base to earn periodic income, but what is different is that the user can convert outdated structures to new ones as they increase their level and unlock new buildings.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.