The game consists of 20 one screen levels. The goal of each level is to collect all the valves that are scattered around and reach the door leading to the next level. Dave isn't alone though as the game's 21 different aliens do their best to stop his escape. In addition to this Dave also has to avoid hitting the deadly spikes that stick out all over the levels. Controls are simple and typical for a platformer - move left and right and jump. When getting close to one of the aliens Dave can also use his shield to kill em off. Problem is that Dave requires energy to function and by using the shield it will be depleted quickly.