This was a lot of fun to play (it's a shame I can't rate it, as I decided not to enter this jam)! The music and visual style kept it engaging and visually impressive, even with simplistic graphics! The only drawback I found was that, since you get given so little life, it doesn't encourage you to face your enemy head-on. Running up to an enemy always meant certain death and, whilst the more stealth-like approach that I took was still greatly enjoyable, I couldn't help but feel, given the other mechanics feeling very 'Doom'-esque, that this wasn't the design intention. More life, or a health-pack system would've brought this game to a whole other level. Regardless, a superior jam entry, well done :)
Edit: upon re-reading the description, I can see now that there were indeed health pickups, they just don't work. Either way, it would be cool to see an updated version of this post-jam