Commander Keen 5: The Armageddon Machine (DOS) - online game | RetroGames.cz
Commander Keen 5 Level Maps
Commander Keen in Goodbye, Galaxy – Episode Five: The Armageddon Machine | Extra Life
Vintage MS-DOS game Commander Keen: Goodbye Galaxy Floppy disk 5,25 inch, 1,2 MB | eBay
Planes of vulnerability in Commander Keen 5
Original tilesets for Keen 1-6, so that users can modify (custom recolored VGA tilesets for Keen 4-6 avaiable here) - Page 4 - Public Commander Keen Forum