This was nearly perfect, in my opinion. The only thing that could've made it perfect would've been a bit more forward with the theme, though I'm not sure how exactly that could be done with the same feel of the game. The old gold, while there, could've been nearly anything else not gold and the game would've been the same, like it wasn't the quite integral enough for 5 stars there. If you found a way to make it more integral to the game, man, this would've been 5 stars across the board for me. Also 0/10 for realism, I've not found a scuba kit that let's me stay under that long :P
Great job!