DERE EXE: The AppSir Prequel is a pixel-based 2D platformer with a retro pixel-art aesthetic and a story-driven single-player campaign. It has been developed by AppSir Games in the same style as its previous games, with the same 2D retro pixel-art aesthetic and the same type of story-driven single-player campaign. The game's title and the game's plot are based on a prequel to a horror film, Dere, which is about a boy who finds a strange, creepy map in his home, and who must go on a quest to find out what's really happening in the house. The game is set in a house in the middle of the countryside, and the player can explore different rooms and the basement in the house.