Lightmatter is an atmospheric, first-person puzzle game set in a mysterious experimental facility where the shadows will kill you. Players must explore the environment while solving challenging puzzles that require them to master different light sources in order to progress through the story and survive. The game follows a sci-fi plot involving a maniac inventor who has created an ultimate power source called Lightmatter. As players progress through the sprawling tunnels and rooms of this facility, they must watch their movements closely or be swallowed by vast darkness.