I'm pretty sure if you're getting sunburned that quickly it's because the sun is actively detonating and no amount of shade will protect you.
Neat idea for a game! I thought it was pretty fun, though somewhat difficult. Level 3 got the better of me unfortunately.
Visually this is pretty great, and the narrative/motivation is pretty funny too.
I noticed the shade collision could act kinda weird under certain circumstances, particularly when two distinct shade objects are next to each other or overlapping. If you leave one while in the other you'll start taking damage. No idea how unity works, but if I had to guess I'd assume the game only recognizes that you left a shaded area and not that you're still in one since it would have last received the signal (or whatever the unity equivalent is) that you left. Didn't hold this against the game though, bugs are almost inevitable in jams, and it was pretty easy to avoid once I realised what was going on.