Great work, I'm very impressed how good of a polished experience you were able to create solo. The best parts for me are definitely the amazing graphics and the feel of the game. It really feels and handles very well. I didn't have much time to play so maybe I missed some things but it does feel like there isn't much to do aside from running and gunning but I think you already did more than most could realistically do on their own in1 week.
Few small hiccups for me. I'm one of those annoying users that's both on linux and using an ultrawide (21:9) monitor. I had to actually get a 16:9 monitor from the attic to play your game because part of your UI is rendered off screen when you play in ultrawide (and I couldn't find a way to change it to windowed mode). And I had to crank up the sensitivity to max in order to make the game playable for me. This has been an issue with other unity games on linux and I don't think you're at fault for that.
Either way great work, I'm very impressed.