Really cool idea! I attempted to join the jam but failed to come up with a unique idea! Great and unique interpretation, really like it! May I ask, since I also use Unity, how you managed to have only some objects cast shadows?
Thanks! I use the URP and the Shadow Caster 2D component on objects I want to cast shadows, and I don't use it on objects that I don't want to cast a shadow. Sad to hear you couldn't make a game/: it happens to everyone, good luck in the next jam!