Doom Delta is a gameplay mod for the GZDoom sourceport that aims to incorporate various elements from the pre-release iterations of Doom. This includes early HUD designs, unused weapon and monster concepts, and four unique playable characters.

• Four unique playable characters from the Doom Bible!
• Three fully functional HUD styles, including the helmet HUD from Doom 0.3!
• Weapons such as the Rifle/Bayonet, the Dark Claw, and the Unmaker!
• New enemies such as the Gargoyle and The Blob!
• Score system with treasure items and kill bonuses!
• Reimagined powerups such as the shields and the Chaos Field!
• Vanilla-style sound design!

Yep!

Doom Delta 2.4.0 requires GZDoom v4.7.1 to run. You will also need Doom, of course! Either Doom or Doom II will work. You can also view the changelog!