I'm curious about the audio issues, do you remember what you were doing before it started happening? Were you playing the browser or windows version? I've tried spamming the pause key while playing today and couldn't recreate it.
For the wave softlock issue, do you remember what the last enemy was that died and how they died? Did nodev-tan show up to gloat that wave?
I can confirm that the upward punch causing them crabs to change random directions is a bug lol. I never bothered to fix it because I thought it spiced up gameplay a bit. Your guess is pretty close to the cause, the way I coded the tile bumping feedback was really jank.
For WASD controls, which buttons do you think would work best for punching and jumping? The ability to remap controls was on the list but I didn't have enough time to get it in.
Thanks for playing!