Commander Keen 5: The Armageddon Machine is a platform game, the fifth in the Commander Keen series as a whole, and the second in the second series Goodbye, Galaxy.Eight-year-old genius Billy "Commander Keen" Blaze, having learnt about the alien Shikadi's plans to destroy the galaxy, arrives on board of their ship, the Omegamatic, in order to destroy it and prevent the evil deed. The objective is to reach and destroy the core of the Omegamatic, but before this happens, Billy must find and destroy four machines which protect the main elevator. The game begins with a top-down map of the Omegamatic. This is the level select screen, where Billy can walk around and the player can choose the next level they want to enter. On each level, Billy has to either make your way to the exit, or destroy a vital machine if there is one on this level. Once a level is completed, Billy ends up back on the overhead map. The levels are full of enemies, mostly robots of various kinds. There are also many deadly hazards. If Keen gets shot or touched by an enemy, or falls into a pit or touches something hazardous, he dies and loses one life. Thankfully, Keen can stun most enemies with his raygun. He also carries a pogo stick which allows him to jump very high. Other items to find include: ammo, gems and keycards that are needed to open locked doors, bonus items which give score, jars of "Vitalin" (100 of them give an extra life) and the rare Keg O' Vitalin which gives an extra life.