Fun little puzzle game! One thing that's awkward is trying to move diagonally. It's usually optimal to move diagonally, but if you don't press the two directions at almost the exact same time, you'll move cardinally as well, which wastes water. One fix might be to make it so you have to press a button while holding the direction to move, so diagonal inputs aren't an issue. I really love the vine and flower effects when you beat a level!