Your job is to basically find the end-of-level boss, and then defeat it to obtain the key that will open the level exit, but your task is made difficult by the planet's inhabitants. Get the jet-pack to make it easier to navigate the level and shoot any inhabitants that get in the way. These inhabitants will leave behind something that you can get to increase your score, and the inhabitants will eventually regenerate. If any one of them touches you while you have the jet-pack, you land on the ground or the nearest platform, and have to get it again; and the same rule applies to the key.