Thick Fighter is a game in which you play a small creature which moves in an environment of solid matter, ladders, and ropes. There are two different kinds of matter. One can be destroyed by explosions (caused by bombs and missiles) and the other is indestructible. There's also explosive matter, which will blow up when hit by a bomb or a missile. What each kind looks like depends on the look of the scene and can be discovered through experimentation.