The play screen presents a flat surface that has numerous insect-like icons moving about, each representing a "creature". The player can nudge the various creatures to alter their direction and speed. The goal of the game is to get similar creatures to bump into each other - when enough are in a clump, they will evolve into a more advanced creature. Each game allows a small number of special moves, which swap two creatures' places on the screen.
When the player has traversed the evolution tree for a given screen, that stage of the game is completed. Play then proceeds to another, more difficult screen. The game consists of a total of twenty-five screens, each offering a slightly different evolutionary problem.