(Some spoilers for the whole game (and general Sokoban tips, I suppose) ahead)
Neat game! I like the particles that appear when you're pushing crates and when you've pushed one into a target spot. One level transitioning to another via the sliding camera is cool too.
I think most of the puzzles might've suffered from not too much puzzling stuff going on and instead just going through long paths to get the boxes to their targets that are either a few tiles away or have to be hauled over several tiles. (I liked that the last level spelled out "THX" which I assume is you saying thanks to the player for playing the game though, it's a cute touch!) Seems odd to call it this but it feels like Sokoban busywork which isn't horrible, but can be eh when not done sparingly or with enough puzzling moments to balance things out. Still, some Sokoban principles can be seen like being cautious with boxes up against walls/other boxes and corners. I also like what was done with the ice once it was introduced, was interesting to see that it only moved you two tiles forward as opposed to making you slide until the ice stopped, but it's fine! Led to some interesting moments where you had to have the right parity in order to continue pushing a box on ice tiles with dark pink squares on them.
Also, this above level had confused me the first time through because for whatever reason, I decided to go into the right lane first and when I pushed the box there to the target, I didn't expect the level to end since I thought all the targets needed to be filled for the level to be completed. To keep with the consistency of such a requirement, yet show that boxes can't be pushed onto ice tiles that don't have a dark pink square on them, maybe you could make it so you still have the two paths, but they lead to a large square that has only one target inside (or branching off from it). Something like the following (please excuse the poor cutting and pasting, hope my point gets across though):
Lastly, a small nitpick as I quickly got used to it, but I think the way the walls look in comparison to the other objects (player, boxes, targets, etc.) make it strange to imagine the tiling of the grid space they move through, if that makes sense. It's most prevalent in places where turns/intersections occur or there's one tile in between two objects like here:
I dunno, it just felt off to me at first.
Overall though, this is pretty noice for your first Pico-8 game!