In Substratum you play as an astronaut who is stranded and has to explore an uncharted planet. Much of the game is about figuring out what to do when you encounter the glowing rocks, since shooting at them can cause disorientating effects that are only pertinent to their colour.
Because of the way the puzzles are designed, you’ll often get into situations where it’s not possible to leave the room. To solve this problem you can press the R key and undo your recent actions one room at a time, all the way back to the first screen. It takes a while to wrap your head around how the glowing rocks work, but once you do then you’ll want to try all sorts of things just to find out how you can break the game.
Substratum is available to download at itch.io, Game Jolt, and from its Ludum Dare entry page.