Trying to go through a bunch of these games, but there's soooo many!
Here's my game if anyone wants to try it out. What I did with the theme was to make it "Only One Color", where you can change the color used in the world and depending on the color, the properties of the world (where you shoot your bullet) will change.
https://itch.io/jam/gmtk-2019/rate/461706