Solo dev here, I missed a lot of sleep making this game by myself in time: https://itch.io/jam/cgj/rate/476719
I have participated in two other jams, but this is the first project I've ever taken seriously and finished. This jam felt like my first REAL jam since I didn't put nearly as much effort into the previous ones and there was no communicating with or receiving feedback from the other submitters, nor any sort of competition or prize.