Love the idea, thought and polish you put into this. As simple as the idea seems, it is a perfect fit for a compo, as you managed to show off with nearly no bugs.
The solid main mechanic and cleverly chosen really show the thought you put into developing each aspect of the games gameplay mechanics, for example I really liked the ability to air jump to save myself from falling off my shelf, also gives the game a faster feel. Unfortunately, I experienced some issues while using the forcefield, which triggered the barrier with boxes and thus resulting in a game over, but overall, I like the uniqueness of the powerups and their appearance in the game (although stomping seems overpowered :D)
Graphics are aesthetically pleasing and look polished and well thought through (for some reason I really like that wall texture :D) The menu screen transitions and ability to jump in the game over screen give a juicy feel to menu navigation, which could be further improved by enabling directly stepping through the menu using the keyboard or controller. Speaking of UI improvements, I think the barrier activation could also be visualized in a more noticeable way.
As other commenters have suggested some kind of upbeat soundtrack would be nice, but I also appreciate you not putting in an unnerving loop, which would ruin the game.
I would love to see a competitive couch co-op or mobile version with a global leader board. My highscore up until now was 39 boxes, so I guess I have to step up my game a bit to beat @amras0000 :D
I rate this a perfect 5/7.
PS: I also enjoyed reading your development log. Keep up the good work :)