Mobile world is changing so fast… Less than 3 years ago, I've recommended a game called ZNax for Windows Mobile. Sigh… good old Windows Mobile… I really liked it back then, the game was addictive, it had the element of time (countdown) & competition, it was challenging and addictive. Today I found this game (ZNax) in WP7 MarketPlace! The exact same game, probably implemented in a slightly different way but still kicking.
The purpose of the game is to create rectangles of the same face/color to gain points. The bigger the rectangle is, the more points you earn. Fun game, believe me.
The new version is a bit harder to play as it misses the visual indication of the selection you actually make with your fingers, but since I knew the game I figured that out quite easily. People who do not know the game might find it a bit hard to play at first (I also saw some bad feedback in the comments section because of that).
Nevertheless – I recommend you download it (it's free!), try to play and see if you like it. I did.