Doom source port in Lisp

In the last few years I've been watching Doom videos a lot, particularly Decino's, and I've resumed playing occasionally, marveling at modern maps such as Ancient Aliens and Auger; Zenith. I suck, but I have fun playing. I love programming and I love Lisp, but haven't done much Lisp lately. So I'd like to 1. write some Lisp 2. understand Doom (and games) better, from a programmer's point of view.

1. Port the open-source DOOM engine from Id as faithfully as practical
2. Refactor it to make it Lispy (possibly looking at other ports such as Mocha DOOM)
3. Implement more modern features:
   • Boom
   • UDMF
   • Etc.

Useful resources and pointers:

• The open-sourced DOOM engine from Id Software which will be the initial source of inspiration for this port
• The Mocha DOOM implementation in Java for ideas for translating low-level C code to a higher-level language
• The CL-Dwaddle library to manipulate WAD files
• CL-MeltySynth to play MIDI possibly to play MIDI music if cl-sdl doesn't work