The story and concept are neat. The audio is also not bad, though I agree with what others said regarding having a bit more ambience. The sonar system confused me. I assumed it scanned in all directions so I would repeatedly use it every few seconds, but I usually can't make it more than 20 seconds into a level before I'd hear multiple obstacles that I couldn't avoid and died. Perhaps I'm misunderstanding how it's supposed to work, but after reading the help and playing the game with audio alone (I'm completely blind) I sadly wasn't able to get very far.