I enjoyed my run, and reading over the comments my experience seems to have a lot in common with others here. To add on two notes I haven't seen yet:
- For the middle portion of the game I regretted taking the second gun upgrade. When the enemy density is low you tend to want to shoot exactly the right amount of bullets, but since most of the slimes take an odd number of bullets to kill (not accounting for extra ricochet damage), you can't do that perfectly anymore. Similarly I avoided the fire speed upgrades for too long for the same reason, and ended up regretting it towards the end when waves got denser
- I noticed that when standing near a wall I could sometimes have one of the two guns fire bullets that act as if they have already ricocheted once, maybe because the gun starts behind the wall and the bullet passing the wall to enter the gameplay region counts as a hit?
Overall though I had a good time here, you did great work!