So, related to my last question.

Is anybody willing to make or talk about a proof of concept 3d open world using Doom's source code? You'd use said world to travel from song to song in a similar fashion to the Undertale mod.

Okay, so this is merely a question.

Could you theoretically run Doom inside of Friday Night Funkin'? Both games are open source, but I don't know whether people just haven't thought of it yet, or if it isn't possible.