Pac-Keen is a fangame created by rorie1983 with GameMaker and released in 2003. The latest version dates to 2005, which includes additional levels and Paddle War. Pac-Keen is a Pac-Man-style maze game using Keen graphics and sounds.
Commander Keen has to collect all point items in a maze while avoiding the deadly green Foobs. Touching them costs a life, but they temporarily turn into vulnerable red Foobs whenever Keen obtains a Neural Stunner. After defeating a Foob, it immediately respawns in the maze's center. Occasionally, a Lifewater Flask appears that gives an extra life. When no point items are left, the player advances to the next maze.