Cosmo Gang: The Puzzle is a follow-up, but otherwise unrelated, to Cosmo Gang: The Video. Gameplay is similar to Tetris, as falling pieces made of blocks fall from the top of the screen.

The goal is to make left-to-right lines with the blocks, clearing them. Occasionally, a piece will contain either Cosmo Gangers or attack blocks. Cosmo Gangers block your way and make it impossible to progress. Attack blocks, however, get rid of Cosmo Gangers, earning many points. The game is over if the blocks hit the top of the screen, and to make it more difficult, the closer they are to the top, the faster they drop.