This was really fun! Okay also some parts were a little frustrating like the what the merchant wanted (not having water was a bummer) but I don't think it would be satisfying without it. Also given the game length the difficulty gave it a bit of a roguelike feel that made we want to do another run "this time I'll save a star in case theres no water". On my third attempt I was able to finish and I was pleasantly surprised at the extra fuel turning into flowers.
Gameplay-wise the crafting was simple but the time constraint + physics move made it fun and I'm really glad you had slightly different mechanics for the different shapes. I'm not much for 'clicker' games so having the circles be time-gated and water 'expire' instead was a great choice in my opinion.
I realized there were harder difficulties so I may have to come back and try it again.