Alexey's Dwice

Alexey's Dwice is the brainchild of Alexey Pajitnov, the creator of Tetris. Its premise is simple: you're presented with a screen, in which a group of various shaped blocks drift towards the bottom. The goal is to prevent them from doing so, by matching blocks with the same shape and clicking on them. Each pair explodes, and momentarily stops the downward movement of the others. You can score more points by clicking on same shapes with the same color. There are also items that you can get, such as dynamite (explodes blocks and creates smaller simple shapes like squares), an icepick (destroys one shape), and a fire line (clears the entire screen of blocks).

The game has two modes, quest and arcade. In the former, you choose a starting location on a map, and play to unlock other locations, which are of increasing difficulty level. In arcade mode, you just play, hopefully bypassing levels that are progressively more challenging (ie. more than one screen of blocks to monitor).