Game: Commander Keen 3 :keen must die

Keen travels to the Vorticon homeworld in search of the mysterious Grand Intellect that has directed the Vorticons toward Earth. The game features the cities, parks, and suburbs of the Vorticons, and their women, children, pets, and mechanical toys make up the enemies. The Vorticon alphabet is also decoded in a school house, allowing for the player to travel to the other in-game locations and read the Vorticon signs. Although finding that isn't actually necessary to decipher it, save for a few letters that are never used in other actual signs, the sheer quantity of signs, starting from the "exit" signs, and a few humorous pun-based jokes that resolutely peg it down like "fort canavort" make it all fall into place fairly quickly.
Each game uses different controls, most DOS games use the keyboard arrows. Some will use the mouse , "Alt" ,"Enter" and "Space bar".