DOOM 64: Unseen Evil (2024)

Doom 64: Unseen Evil (or Unseen Evil for short) is a mod for GZDoom that transplants the Doom 64 atmosphere into Doom and Doom II. In addition to replacing various monsters and items with their Doom 64 counterparts, Unseen Evil also uses ZScript to transform existing Doom levels into Doom 64-style locations.