This is great - deceptively simple mechanics used in very clever ways, with a well judged increase in difficulty and complexity as the game progresses.
Only a couple of minor things that could be improved: The tutorial text disappears too quickly; I had to restart the game to read it again. Either have the player push a button for it to disappear or integrate it into the environment (e.g. posters on the wall) so the player can look at it for as long as they want. At first I thought the resizing wasn't working because I was trying to pick up an object with the mouse button and then press Q/E while holding it. Perhaps allowing the player to resize an object while holding it could make it more intuitive. The falling boxes are very hard to catch; after trying a few times and failing I assumed that must not be what I was meant to do. You could make the boxes bigger, closer or increase their number or predictability to alleviate this. With some of the jumps in the falling box section it wasn't clear if I could make it or fall to my death; maybe make them a bit shorter so it is more obvious or introduce some kind of safety net (ie a platform underneath with steps back up) so the player isn't afraid to try.
Finally, make more of it! I'm looking forward to playing the completed version.