Play Commander Keen 9: Battle of the Brains Online

Game Overview

Commander Keen 9: Battle of the Brains is that rare fan-made sequel that actually feels like the real deal. You’re back in Keen’s sneakers, dodging aliens and collecting keycards aboard Mortimer’s ridiculous space station—this time to stop him from blowing up a star (because of course he would). The first level drops you right into that classic Keen vibe: chunky pixel art, weird little enemies, and those satisfying pogo jumps.

What surprised me was how well it nails the pacing. One minute you’re bouncing through a neon-lit lab, the next you’re sneaking past security bots in some industrial maze. There’s even a callback to the Vorticon mothership if you know where to look. The controls are tight, though I still occasionally overshoot a jump and faceplant into a Shikadi drone—some things never change.

It’s clearly made by people who grew up with the originals. The humor’s still goofy (Mortimer’s new "Universe Toaster 3000" is peak McMire), and the music has that same bleepy charm. If you’ve ever blasted through Pyramid of the Moons or Goodbye Galaxy, this feels like coming home—just with slightly better explosions.

Each game uses different controls, most DOS games use the keyboard arrows. Some will use the mouse , "Alt" ,"Enter" and "Space bar".