Hello there,
It's looking like a fun game! I wasn't able to play it long, maybe 6 rounds or so before getting the error: WebGL context lost. Firefox, latest version, Win10.
I found the mouse control to be a bit floaty even after turning CRT off, and collecting the souls was a little unclear, and the upgrades feel a little linear.
In essence, it feels like a lot of games lately in that Nodebuster genre. Sadly, I didn't reach the parts of the game that must make it different though.
Good luck with your project!