The first thought that comes to mind is... why is the isometric movement not aligned with the actual grid?? I think I know why, but either way...
I like the original take on the 2 character puzzle theme. There's just two items, not too much but still enough for varied level designs (and for me to get stumped at midnight about 7 levels in). Takes me back to when I first designed my own puzzle game - it takes effort to really make something with the simplicity.
I also liked the SFX other than the main menu, they played at the correct time with fairly accurate sounds. It gave a reason to try collecting stars even though the game doesn't promise a reward for doing it (other than a cooler win level splash).
For further criticism though, I wish the game atleast had music, not having music REALLY put me off from playing a long period of time. I know it's a jam entry, but spending the time resource to make simple music would've helped it tons. I also wished the sea waves were animated sprites, like a slower version of the 2-frame animation and scrolled slowly diagonally or something.
That's about all I'd say within this comment section. Congratulations again for making a game together within 48 hours!