The developer of the online game Boomshine has sued Facebook for copyright and trademark infringement for allegedly allowing another developer to offer users an app that resembles the game.

Daniel Miller alleges in court papers that the Facebook app Chain Rxn "copies the look and feel of Boomshine by incorporating almost every visual element of the game." Users play Boomshine and Chain Rxn by clicking on a moving circle that expands, which results in other circles expanding.

Miller, a resident of Marietta, Ga., alleges that the Chain Rxn app appeared on Facebook in April. He says he asked the social networking site to remove the app in May, and also asked the developer to take it down. The developer allegedly responded by preventing Miller or any of Miller's Facebook friends from accessing Chain Rxn.

Miller brought suit against both Facebook and the developer of Chain Rxn, Yao Wei Yeo (who does business as Zwigglers Apps), late last week in federal district court in Atlanta.

Facebook said in a statement that it sees no merit to the case and intends to fight it.

As of Wednesday afternoon, Chain Rxn was still available on Facebook, where it has more than 900,000 active users.

The Chain Rxn app also became available on the iPhone store earlier this month. Miller has not yet taken legal action against Apple.

Boomshine is not currently available as a Facebook app, but can be played for free at the developer's Web site, Ktxl.com.

Facebook has confronted at least one similar complaint in the past, although that did not escalate into a lawsuit against the company. Last year, Scrabble manufacturer Hasbro demanded that the site remove look-alike game Scrabulous. At the height of its popularity, Scrabulous had more than 2 million users.

Facebook eventually took down Scrabulous, but the developers returned with another word game, Lexulous. The Lexulous app now has around 387,000 active users, while the official U.S. Scrabble app has around 485,000.

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