This is actually really well designed, the visuals were incredibly well made, especially the backgrounds. I found the progression of how the boxes were used really well done, it started simple and slowly changed to include more complex uses of the boxes in such a smooth way I never felt stuck or blindsided. Maybe one or two sprite/color variations of the boxes would've been nice but that's such a small insignificant thing that it doesn't matter.
There is the clunk problem with control over the boxes but I 100% believe the atmosphere you created was worth spending the time on, rather than perfect pristine controls. I really enjoyed playing through this one, Great Job!