You can add one more entry into the already crowded "free-to-play FPS" genre. This week Korean-based GameHi announced that their title Sudden Attack was coming to the US. Furthermore the game is letting people sign up to beta test the game right now.

The closed beta has already begun and will end shortly on May 31. The game itself was launched in its native Korean in 2006 and the publisher claims the game is the most played FPS in that country. Sudden Attack has a lot of similar elements to other games in the genre (team-based gameplay, support for up to 16 players, upgradable weapons and items). It also has some unique elements such as an in-game water battle mode. There's no word yet on when the official US launch of the game will happen.