Basis: A fast paced puzzle game.

Gameplay: Seriously insanely addictive
Graphics: As far as XBLA goes, pretty solid.
Story: Not Applicable
Sound: It suits the game perfectly.
Enjoyability: Most addictive game I've played on XBLA

Bottom Line: This is the most fun game on the XBLA. Great waste of time, and definitely worth the full 800 MS points.