Overall, everything I wanted to suggest was already mentioned by the previous commenter. As another idea, you could add a speed boost for the player when moving upward, so it’s easier to surface in time. Thanks for the game!

The player character moves super slow, I'm just barely able to hit the first quota. Why have it in the first place? There are already two separate timers pressuring the player.

It seems like more fish spawn deeper down, but you can't get far enough down and come back up before your air runs out. You can upgrade your speed and air capacity, but you have to spend points, and if you spend any points you can't hit the quota and lose the game.

This could be fun with faster movement speed and a little less pressure.