This was really neat! I love the idea of using the microphone to capture sound effects from the player. That said, in Chrome on Linux the recordings weren’t the best. Sometimes it didn’t seem to pick it up and when I did get them they seemed sped up. Maybe some kind of sample rate issue?
I also got stuck on an edge in the cave, and couldn’t figure out how to respawn, so I just bailed out.
Regardless, really neat concept, nice job!