I saw this yesterday and got pretty excited. A while back, I stumbled across the same source of inspiration: http://www.lwh.jp/lisp/index.html
Being mainly a CL hacker who came from Python, Arc has looked interesting to me for a while, but I couldn't justify running a small language on a HUGE backend like Racket... So I started implementing the environment described at the link above, which you did as well. Incorporating my initial work with quite a bit of yours, I spent 24 hours hacking together something similar. I haven't done nearly enough to it yet, but I added some new types and support routines. The code layout is slightly reminisce of Quake code. Take a look if you're interested: https://github.com/camden-smallwood/arc