No problem! As for the feedback:
I think what you have is stellar (pun intended). I like how you slowly introduce new mechanics over time, and the puzzle you have in the game so far are great! A few suggestions that I think could make the game better overall:
1. I think some more varied and interesting music could help quite a bit rather than the droning sound you have right now
2. I think that the sound effects could use a bit of variation, and the current gravity change sound effect get's a little annoying after a while
3. The graphics are a bit under par (which is understandable due to that fact that this was a jam game.) I think if you refine the art style a bit and add some polish, it will look a ton better
4. I think that there should be more puzzles where the player needs to use the movement keys. I could solve most of the puzzles without even touching the movement button, so I think that the movement mechanic could be utilised a bit more.
5. More levels!
5. I think adding some smooth gravity to the sand would be good considering everything else moves smoothly. Them moving by increments like they are now makes the game feel laggy even though it's not.