Awesome game! Fun, fast-paced, almost half-life vibes. Played through to the end wanting more, and I'm not even an FPS guy. A few things I would like to see: AI movement like strafing for some challenge, better AI detection (I could often see and shoot them and they are standing still because they are far away), maybe a bit of telegraphing on that enemy that kills you on contact (the atmosphere for that part is really cool though).
I noticed a lot of nice touches you don't often see in jams like bullet decals, cool bosses, and some good atmospheric storytelling. Music suited the game really well. Nice job, hope you work on it or something similar post-jam :)