Kerker

Kerker is a puzzle game featuring fixed-screen maze-based levels with key collection and environmental interaction. The game follows Koen, a member of the human resistance against an alien occupation. After refusing to submit to the alien authorities, he is imprisoned in a deep dungeon—referred to as “Kerker,” roughly translating from Dutch as "prison" or "dungeon"—and must escape by traversing a series of increasingly complex stages.

The game was distributed for DOS as shareware with a first episode covering 15 levels. A second episode called Kerker II is provided after buying the full version. The Windows version contains both straight away.

Levels are filled with traps, platforms, elevators, keys, explosives, and obstacles. To progress, the player must collect all keys on a level to unlock the exit door. Some stages require activating switches to operate lifts or access blocked areas. Explosives can be used to clear certain passages. There are also time limits. The game has no direct enemies. A built-in level editor is provided to create custom levels.