Lumines

Lumines is a block-dropping game, that may seem at first to be similar to Columns and Tetris. A 2 x 2 square (an O tetromino) made of four smaller block pieces is dropped into the playing field, which may appear different as the player advances through levels or skins.

The small blocks that comprise the larger blocks will be one of two different colors. The objective is to rotate and align the blocks in such a way as to create 2x2 squares of the same color, which may span multiple blocks and, indeed, share blocks.