My game is Rely (https://keeptrying.itch.io/rely), a cute-themed CGA colored Shooter and it was actually the second concept i went through during the jam!
I started by making a puzzle game, but after 4 hours I had to get the guts to scrap it as the main mechanic was too complicated to be reasonably done in 72 hours, cause it involved too much AI with an element being escorted in each puzzle.
So then, after being pretty bummed out due to this, I thought that a complete change of genre was going to help clear the air, so I went through and thought how could a theme such as "Take Care" fit in a Shoot 'Em Up, which was a theme that even though I like a lot and am familiar with, never played much with as a developer.
It felt natural to make a game where you controlled two elements simultaneously and one defended another. The tough part was figuring out how to make the movement intuitive because controlling and shooting with both would just be impossible. So after trying lots and lots of movement types out, such as only in straight lines, mirrored, one at a time with a key for shifting, the circular one felt really really good cause one of them naturally protected the back of the one shooting, in every possible position. From there "Take Care" took an immediate meaning as having a playable character taking care of another by acting as a barrier.
I started since the beginning with the intention of doing the Extra Retro challenge, cause it's just an art style that I can't get enough of!
It's really amazing how much limitation breeds our creativity during these events. In no other circunstance would I think of this same concept if I didn't have the conditions given here!