Absolutely loved playing this, I'd no joke buy this if it was on the app store with maybe a little bit more content. I loved how all the upgrades tied together and trying to manage boat position with diver positions. Also it is the perfect length for a game jam game, enough to get invested but short enough that it doesn't expect me to play it for hours and doesn't give me time to grow tired of the game mechanics.
The only upgrade that I didn't find that useful was defense, there were too many divers and too little sharks. Maybe make the sharks kill your divers so you need to buy new ones?
Outside of that the only thing that bothered me was the shop hotkey, maybe it was just me but I kept instinctively pressing esc every time to close the shop, exiting full screen instead. Even on my second play through I couldn't get used to it. I know it is the web player that hijacks the esc key, but maybe using space for it or adding a physical close shop button on to the shop itself could have helped, the one on the top right was too far to press naturally.
Anyways if you ever make this a full release add a stats thing at the end, I would love to see how many shark bites I got and how fast I managed to retire. Amazing gameplay, amazing concept, amazing execution.