That was a lot of fun! It scratched a first-person shooter itch for me which normally doesn't happen in a game made in just a few days! While this is a demo, the core gameplay is there and I think it's working quite well. My only comments are ones that'd be addressed with more polish such as better impact feedback ("Am I hitting the enemy?", "What is my bullet hitting?"), smoother run animations, smarter AI, etc. which are all addressable in the long run.
Btw I enjoyed all the little details in the audio! Filtering the music in the beginning which opens up as you enter a big fight in the main bar room, the pitching-down effect as you activate slow-mo, the music cue changes to help create atmosphere per map section, etc. If not done well, they can become distracting but it's pulled off very well here!