Ludum Dare is a freeform event where entrants try to complete a game from scratch solo within 48 hours. I made a little submarine dive game for Ludum Dare 29, which had the theme “Beneath The Surface”. It’s called 29 Leagues and it can be found here on the Ludum Dare website.
Pretty simple, and I got sidetracked for a long time trying to do something different for the second part that didn’t ultimately make it in, but it’s finished and it plays well enough. I made a time-lapse video of development as well.