I got to level 6, and when I got the 8 barrel shotgun, I did audibly have to laugh :-)
The PSX-style graphics with the vertex wobble is great. I love this style. Recently played Cloverpit, which used similar aesthetics.
I eventually had to stop playing at level 6 because the wobble and glitchyness got way too intense. I think this is intended, but I just couldn't take it anymore. It gave me a bit of a headache 😅
The physics based 3D platform mechanics are great. I'm a big fan. (It's also why I also made an FPS platformer with momentum-based gameplay).
But one downside is that due to the high FOV and low resolution graphics, it's actually very difficult to turn exactly 180 degrees. I was always off by a bit. And it's difficult to predict your movement if you are always going backwards. But I guess that's part of the challenge. :-) Still, a few more markers in the level to indicate where everything is would help.
And finally: If you made this music yourself: It was great and fit the theme perfectly. Always love a good DNB track ;-)