As far as I can tell - you have procedural generation of each level?? That is incredible! The game is super cool, the graphics are clean and there are so many cool things about this game! I have included a few things that I want to note to help your game improve:
1) As someone already said, the footsteps sfx gets repetitive fast and needs variation / probably needs to be quieter - a background sfx to add immersion, not the main thing players hear
2) I feel like the screen shake is a bit on the excessive side - maybe a personal preferences
3) I noticed my bullets would collide with pickups instead of shooting through them as expected
4) The music would change randomly in the middle of one track and feel jarring
5) It was hard to know that I need to find the level exit after I defeated all the monsters - sometimes that was harder
6) A few times a monster spawned inside me so I took immediate damage
7) If a monster is inside my collider, I am immune to any more attacks from any enemy
8) The lag spike from starting a new level made the game freeze for a long time - maybe adding a loading screen?
Overall, super impressive! Good job with the game! It was a lot of fun! Would be cool if there was something new / different added with each level, but got a game jam, this is a really good job!