It started out as a fangame made with Multimedia Fusion that was announced by DaVince in February 2006. The full title is Commander Keen in Return to Gnosticus! DaVince eventually abandoned it and switched to Sphere, but made the earlier game's source available in November of the same year.
Gameplay is aimed to play as much as possible as the original Keen 4-6 games. This means that the main person (Keen) is able to walk, jump and use a pogo stick to jump higher. The abilities of shooting and hanging on ledges were also planned, but are not implemented in the demo. The game was intended to play like a classic platformer.
Anything not mentioned here is simply not implemented.
- Walking and slope walking
- Jumping and falling
- Using the pogo stick
- Collision detection (buggy)
- Looking/waiting/misc animations
The controls of the engine in its current state are the same as that of the original games.
- Keys left and right move Keen around the playfield.
- Key down will make Keen duck. Quack.
- Key up will make Keen look upwards.
- Ctrl will make Keen jump. Jump height is dependant on how long the ctrl key was pressed.
- Alt will activate/deactivate the pogo stick. Keen keeps on jumping low, but will blast into the air once you press ctrl during pogo mode.