After a second glance at today's press release announcing the Nintendo DSi's North American release date, we noticed Nintendo snuck a game announcement in at the end. Rhythm Heaven will arrive in stores on the same day.

In Rhythm Heaven, players tap and slide the stylus on the screen to match the beat of whatever song is playing. In Guitar Hero fashion, players will be graded on their performance based on how closely they followed the song's beat and good scores will unlock additional game content. Rhythm features original music from Japanese producer Tsunku and other artists.

Though Rhythm Heaven will hit stores in North America on April 5th along with the DSi and the game and system are sharing a press release, Rhythm Heaven is not specifically geared toward the DSi. The game's compatible with all three versions of the DS. I guess Nintendo figured they could get some additional publicity for the game by hitching its release date announcement to the DSi press release.