Gameplay takes place over various days, and after a long time passes, the counter resets, though the game can still be played. After the dream ends, it is displayed on a graph showing whether it is considered Upper, Downer, Static or Dynamic. Coming into contact with any object or wall in the dream can result in warping to another part of a dream, which can go on for very long (up to 10 minutes), or can be cut short by falling off cliffs or through floors. The gameplay is simple, walking around various dreamscapes and occasionally discovering surreal visuals.

Inspired by a 'dream journal' written by Hiroko Nishikawa, LSD is basically a simulation-based game themed around dreams and nightmares.