Great puzzles. Got to around the fourth round. The gameplay is great and fun
Some suggestion from my side would be just making him pick boxes or just giving more room to move the boxes. in the this round where you transport boxes I was stuck at the end and did a lot of thing to pass the level. For this you could just parent the object to the player and make it move along with the player(which has its drawbacks but shouldn't be a problem for this game)
And also would suggest the player collider to be a bit small as it really pulls out the 3d kinds feel when you push the box up with your head.
Apart from those no complaints, music was great, click sounds were satisfying.
Kudos!! :D