I really like your concept, the combination of puzzle and survival. Although there is no way to anticipate the next level unless your already reached it. So sometimes your last move will decide whether you pass the next level or not, then if not, you will restart and plan your moves again. That aspect in my opinion is worth improving or at least looking into moving forward.
Gameplay is GREAT.
Very well related to the Theme.
Art is good.
Sound is peaceful.
Overall your game is GREAT! good luck with the jam!