Cube is a free open-source single and multiplayer first person shooter. The game is developed for mac OSX, Windows, Linux, freeBSD, Pocket PC, iPhone and iPod Touch. Developed by one man (Wouter Van Oortmerssen) and the game still don’t lack the graphics and gameplay to qualify as a really good FPS engine.
Level editing has never been so much fun before. With a single click on the keyboard you go from playing the game in to actual in-game level editing. Create a little peace on your map and pop straight back in to game mode. This in-game editing mode will keep you entertained for hours.