In Catrap, you are Catboy or Catgirl, and sometimes you are both in a single stage. Your job is to smash into every monster you see. In each of the more than 100 screens, you must overcome obstacles such as chasms, solid walls, and melting floors, and you must dig in soil, climb ladders, and push stones from side to side or off of ledges in order to get around. Once a stone is up against a wall or in a crevice, it cannot be moved. Sometimes you can even use the monsters themselves as stepping stones to allow you to maneuver around a room.
If you are in a jam, you can restart a stage or hit rewind. In addition to the standard game, you can create and save as many as five puzzles. A password feature is available which enables you to save your progress.