I've ran through it a bit and the only problems I could find were the fact that the cd music doesn't work and that the game runs a tad laggy and choppy. One bug was weird though, in level 2/3 of the shareware episode I remember having to run that vehicle you had to fix through the wooden boxes. Well that didn't work, strangely enough
I found something else though.. I was bummed that I could never get JfDuke to run in full-screen and gl at the same time .. but with JfSw it works
Awesome!
Edit: just noticed the cd music thing has already been mentioned above. The voxels díd work here though.
Final edit: Forgot to mention that if you press F7 you can still see the weapon at the bottom of the screen. I don't know if this is supposed to be like that so if it is forget I said anything.