Mind Walker is a puzzle game where a mentally disturbed professor must enter his own brain to repair it. The aim is to navigate through different landscapes and puzzles, changing into different forms to overcome obstacles. In the first level, the player must connect a path from a certain location to a specific crystal by using the correct avatars with the correct landscape type while defending against hostile enemies that decrease in frequency as the player approaches the destination.
The game requires good timing and spatial awareness as the player guides an avatar around a maze full of pulsing neurons to locate a pyramidal "shard of sanity" using audio cues. Touching a neuron while it pulses means instant death, so precision is key to collecting the pyramid and returning to the exit.
The final stage involves completing a Rorschach-inspired colour-cycling puzzle to replace the shard. The levels loop several times before the restoration of the physicist's sanity is achieved.