So I made this aquatic thing for Windows+Linux called Sunk Coast.
It has cheeky Sea Monkey’s, sunken treasure, magical conches, and an ever dwindling supply of oxygen. Download page is http://jonathanwhiting.com/coding/sunkcoast/, source code is available here https://github.com/whitingjp/SunkCoast.
I technically overran the seven days a little for reasons outside of my control. As far as I know I actually did work on less than seven days though. Failure? Success? I don’t really mind. I’m just glad to have made it.