I appreciate the feedback, it was great to see you explore the game live!
I think your notes make sense, we'll add most of them to our todolist.
The low freq ambient SFX you reacted to was the hum from the geothermal vents you spawn next to - we might tune them a bit if they sounded like a bug. Were footsteps just quiet, or did they glitch out as well?
Fish Harpoon Action will be upped in future updates, better beelieve it