Good job!
Though I like how you can go around the whole level and explore (and fall out of bounds), keep in mind that there always needs to be a goal for the player - be it a literal goal or exploration. This level for me would fall more under exploration, but there wasn't that much to "find". Maybe even adding a key that then opens something at the start would give it more direction for me.
For the box that you have to move to the left to be able to climb the wall. My instinct was to just go push it to the right, because maybe there's a button down there or something. It's good to try and give visual clues in such cases (even something as obvious as an arrow can work very well) and obviously have some way to restart it (though I understand that you don't have that here).
Just to be clear - this doesn't mean you have to go back and remake it, you have completed the assignment. Take this more as food for thought for your next work.