Nice work! The characters and scenes are adorable, and the bouncing bullets add an extra layer of fun to the game. But I think the slime goo is a bit too easy to collide with, and the collision detection feels a bit unclear.
Additionally, if the concept of balance could be emphasized more, it would make the game feel even more in line with the theme. One more suggestion: it would be helpful to provide a hint or direction to the next scene after completing a level, so players know where to go next.