Vorticons also have an outpost on Mars. A total of four Vorticons can be encountered in Keen 1, but it is likely more live on the planet. Each Vorticon is guarding an item they stole from Keen's Bean-with-Bacon Megarocket.
Mars has two sides: the Light Side, and the Dark Side. They are connected by a teleporter. The first seven levels are in the Light Side; the rest, which are the hardest, are in the Dark Side. For details on the levels, see Keen 1 Levels.
A common type of level is the shrine. There are seven shrines on Mars. All of them share some common traits: they are enclosed and dark, illuminated by lamps on their ceilings. The floor is a red Martian rock, and they are built out of grey bricks. With the exception of the Pogo Shrine, all of them are mostly vertical, and have the exit on the top. Furthermore, they have a statue near the exit that delivers a telephatic message when touched. Except for the First Red Rock Shrine, all of them have one or more fire pits inside the shrine. In most of the shrines, there is a Garg protecting the entrance or some treasure. Many of levels have books and/or a teddy bear, the most valuable items in Mars. All the shrines are fairly small, and some of them have additional structures before the shrine entrance.
In the main map and inside the levels, there are some elements Keen can interact with, besides the creatures and items:
- Teleporters: transport Keen to another teleporter in Mars.
- Ice cannons: freeze Keen for a short time inside a block of ice. Keen is invulnerable while frozen (except when landing on harmful objects), though he cannot be controlled. Found in the Ice City and Red Maze City.
- "Commander Keen: Invasion of the Vorticons – Story, Hints and Cheat Mode". id Software.