Still in progress. Use WASD (without the "W") or arrow keys to move, especially to crouch. So far, there are 5 entities and a sub-entity. Don't go backwards too far. Press [SPACE] for debug to see entity spawning. Press [M] to disable sounds, press [F] to reduce fog and press [V] to disable the vignette when entities spawn. Good luck!
The code is 100% by me! Entity Guide: Backtrack - Big smiley face. Listen for the sound effect (or look out yourself) and go backwards to avoid. Stalker - Bright, red, gleaming eyes. Go backwards too. Sin - Red star. Crouch to avoid. Fake - Most entities can be fake. Avoiding them will result in death. They won't attack you directly. Fake appears blue. Wrath - Strange eye unaffected by darkness. Crouch at every heartbeat but not when there is no heartbeat. Wrath can not be Fake. All-Sight - Eyes in a eye. The amount of eyes inside is the amount of rooms until you have to turn back. 662 blocks