It would definitely take some creative interpretation IMHO. That is if you’re using the gameplay of Eternal, you’ll want to make changes to the original maps structure and encounter design. Would be an intensely interesting project to take on… Even just an episode, or a level or two…
I’m already thinking about how to “gate” different sections in episode 1 to work with Eternal’s arena based gameplay. Later episodes and Doom 2 gets easier, though.
The only thing about the level design I think would get broken is the fact you can jump and other traversal methods. The original maps weren’t designed around that, and even Brutal Doom breaks them with the addition of jumping. But what’s broken is the intended progression and access to secrets and is also an easy fix. Just make the barriers higher or gaps further, etc.
