The ambient audio thing had a lot to do with trying to work around music being an aspect of game development that's particularly outside of my skill set - but yeah, it would have been really cool to speed everything up over a bunch of fast tempo techno music or something. Some of the things wanted to do, but didn't have the time for would've been to have shots leave a glowing mark that kind of fades away as it cools down (kind of like when a light saber cuts something) when they hit the walls/floor/ceiling and I really wanted the enemies to burst into a shower of sparks and broken glass when defeated.
Thanks for playing and taking the time to give some thoughts!