In Blow Up! the player takes on the role of Joe Kowalski who must navigate his way to the exit in six progressively more difficult caverns. The game has similar gameplay as Boulder Dash, and each cavern must be completed within five minutes.

Along the way, Joe will encounter various enemies. There are grabbers who will jump on Joe and slow him down. Darth Vader heads who move around more quickly and will shoot at you. Walking grenades will explode when you come too close to them. The green virus will spread around when it is unleashed and it will make you sick when you come into contact with it. Joe will turn pale white, his energy will drain and he can only move around slowly.

Joe can fight back by dropping rocks onto them, or by shooting them or by using mines to blow up enemies or walls.