I have PTSD from Sokoban games from the terrible game I made in my last jam (before this one). So going into this I felt a sense of dread but the atmosphere and pixel art quickly made me feel better about my decision.
There's a good level of polish here and although I haven't got far (and I may well take up your advice of coming back later) its a well through out set of puzzles. I do think you probably could've taken it a little easier on the player at the very beginning, you'd get more play time, interaction and willingness to complete harder tasks if they've already achieved something.
The addition of some actual music rather than or in addition to your low key sound effect would be a good addition.
Visually very cool, smart and interesting. Lots of potential to be built on too.