Really nice entry! I enjoyed playing through all of the levels.
I would have enjoyed if there was a "fade to black" when you died. Sometimes it was dissorienting to be teleported so directly.
The Web version also didn't work for me: mouse wasn't captured. I played the desktop version.
Performance was also quite rough. Probably there were some simple optimizations you could have used (like instanced geometry) that would have solved that. I couldn't find source code though, so I couldn't snoop xD