Hey, thanks for participating in Week Sauce!
This is a great made-in-a-week game, and I can see how you could totally add more features to it: aquatic creatures, sunken galleons, treasures, caves… it could have levels too, so after reaching certain depths there are places where you can "rest", recharge oxygen completely, and upgrade… tons of possibilities!
Anyway, thanks for trying out our game jam, and hope to see you back doing more games with us.
Cheers!