Cube Crash is basically a block removal game, with a few twists.
You start with a large field of a LOT of blocks, mixed up, a lot of different colors. You can remove the block in groups of 3 (or more) that are contiguous (touching). As you remove blocks, the shapes "collapse" toward the middle which would create more contiguous groups. The idea is to keep removing the groups until there are not too many left (how many is too many?)
As you advance in levels you get more colors, more randomization, making your choice more crucial.
The game is simple enough, but can get frustrating a bit later, and it's ultimately a bit too plain.