Just when I was certain there was no new way to combine tapping fingers and music on the iPhone, Reisuke Ishida marries the aesthetic of his award-winning Space Invaders: Infinity Gene with an equally gorgeous collection of tracks in Groove Coaster.

I initially purchased Groove Coaster from the iTunes App Store yesterday simply because it was a new game on sale for $.99 (it goes up to $2.99 after August 7), and I certainly wasn't planning it to be the Gaming App of the Day for today. I've played just about every rhythm game the iPhone and iPad had to offer, so there was no way this one would stand out. I downloaded it, loaded it onto my phone, and fired it up during a cigarrete break yesterday afternoon.

I've barely put it down since.

It's not that Groove Coaster is overwhelmingly different from other rhythm games. There's a single line track that winds itself around each song's level, dots indicating when the player needs to drop a thumb to the touch screen. At its core, it's pretty basic.

It's the tweaks and twists Groove Coaster adds to the standard formula that make it so damn compelling. An experience point based levelling system is in place, with each new level unlocking new skins and avatars, the latter of which grant bonuses or special powers to the player. There are hidden ad-lib sections on each track, allowing creative players to score extra points for extending the rhythm beyond the music.

On easy mode the tap markers simply appear on the shaped line the player's avatar follows, twisting through 3D space as the music progresses. Amp up the difficultly level and things start to get more complicated, dots flying from off screen in swirling, bullet-like patterns, hitting the track just in time for the player to tap. It's a gorgeous dance, evolving its Space Invaders: Infinity Gene roots into a celebration of sound and rhythm.

Amd what dance would be complete without music? Groove Coaster comes with sixteen tracks, from video game themes to electropop to rock 'n roll, with more available for purchase via the in-game store.

The game even intergrates social features via Apple's Game Center, granting advanced scenery in the player-specific Beginning stage depending on the number of friends have played the game.

Groove Coaster is one of the most beautiful combinations of music and gaming I've experienced on the iPhone, and with new tracks, avatars, items, and skins being added on a regular basis, it's an experience with real staying power. Well worth $2.99, picking it up for $.99 during the introductory sale is a deal no rhythm game fan should pass up.

Groove Coaster [iTunes]


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