It would be very cool, imo, to even have the levels the same (same layout) and even the "hidden" areas in the same place, etc, but update the graphics, use actual 3D models instead of sprites for the enemies, etc. Imagine the original Doom made with the latest Doom or Unreal engine.
Maybe not the latest Unreal engine, but check out Doomsday engine.
It runs with Original Final/Ultimate Doom 1/2 Hexen Heretic WADs using a modern 3D Engine with lighting features.
Also there is a lot of user provided content like 3d models which nicely integrate into the game and replace 2d sprites.
Users have provided TONs of hires texture packs.
Check it out, it's a lot of fun!
It made me play through Hexen + Deathknights Addon one more time although I had a lot more modern games on my PC installed.
