Nice work! I enjoyed the survival mechanic but I do wish that I progressed to the next level immediately upon using the last water. It took me a moment before I realized there were upgrades between stages, but I think they really improve the game loop. I'm sure this would happen with more time, but I'd love to see a some level variety as well as the ability to re-map input in the controls. Loved the graphic style. I encourage you to keep going!