A new social game developer called Rocket Ninja is emerging this morning, with a recently released Facebook title, $3.5 million in funding, and an unusual publishing platform for other developers.

Rocket Ninja has actually been around for two years, but never released a game. Its founders intended to release a 3D Flash MMO, but like several other startups with similar plans, switched their focus to Facebook when that platform’s promise became clear.

The 3D engine, called Shr3d, is still in the works. Rocket Ninja has a blog post about the technology that gives a few details, but the coming out party for the engine is being reserved for the company’s second game release.

The first game is a virtual aquarium title called Ocean Kingdom that’s unlikely to blow away anyone in the Valley — aquarium games were common in late 2009, but new releases in the genre have been rare this year. But Ocean Kingdom isn’t aiming to be a hit game. It’s instead a sort of demo of what Rocket Ninja does, or can do, for partners.

Rocket Ninja’s hope is that other developers will choose it as a publisher; in exchange, it offers three main services. The first is invisible in Ocean Kingdom: the game’s back-end, which is part of a platform that the company developed for use in multiple properties. CEO Oded Pelled, who was brought on by the new investor, says one of the biggest problems in social gaming is weak back-end architecture, which results from teams spending most of their time focusing on the front-end game.

So Rocket Ninja will migrate existing games to its own back-end and run them for the developer. The second technology the company offers is personalized virtual goods offerings for players; once a player has shown preference for certain kinds of goods (in a dark or light theme, for example), the in-game store will use Rocket Ninja’s algorithm to show personalized offerings, which should increase purchase rates.

The last part of Rocket Ninja’s offering to potential partners is user acquisition, much like existing publishers like 6waves offer.

Although Rocket Ninja seems to be pursuing a lot at once — perhaps too much, for a startup — its plan is really just to develop tools that it finds necessary in social gaming, and then share those with smaller startups that don’t have as much financial backing or technical expertise.

In the broader view, Rocket Ninja is just one of several companies trying to figure out what the right model for publishing is in social gaming; we’ve seen companies offering financing or promotional expertise, but sharing a unique technology platforms may also be a viable route.

So far, the company is planning four releases, split evenly between two of its own and two from partners. Its first 3D release is likely to be the first one out, which should help prove both Shr3d, the in-house tool, and the true strength of Rocket Ninja’s back-end and store ranking systems.

The $3.5 million funding was provided by a single European angel investor, who hasn’t yet been named by Rocket Ninja. The company is also announcing a couple executive appointments besides Pelled, which we’ll cover later today in our weekly hires post.