Rating: 4.7/5
The Plutonia Experiment was made by brothers Dario and Milo Casali, and is a 32-level IWAD for Doom. Along with TNT: Evilution, it is part of Final Doom, and it is considered to be the harder half.
You also need an emulator to run this game. To grab one quickly, please check out our DOS emulators section.