Tucked within the press release for the Nintendo DSi announcement was the reveal that Rhythm Heaven -- a music-focused DS game -- will ship in the US on the same day as the brand new system: April 5, 2009.
Rhythm Heaven is a game where players use audio and visual cues to tap and stroke the touch screen along with the music. The closer and more accurate you follow along, the higher you'll score. The game is a sequel to Rhythm Tengoku, a 2005 Game Boy Advance title that was only released in Japan.