Watch the vent. Trust the door. Survive the night. Tip: This game is easier with sound on! (Don't turn the volume too loud though)
Scott Cawthon and the Five nights at Freddy's Franchise for all the ideas since this is technically a fan-game. Many sounds taken from Fnaf franchise and the Roblox game, Doors (made by LSpalsh and Redibles). Vent's click sound effect from Minecraft.