This was an absolute blast to play through, and I loved the messages along the way. When I first started the "OH" moment I had when I realized that the blocks have gravity was spectacular, and the future puzzle of fitting your limited building blocks together in order to reach higher and higher was lots of fun. Just thought I'd give some design ideas if you decide to expand on this game in the future.
First of all, I think the existence of the floating blocks that you can place is somewhat detrimental overall. At least for me, one of the most fun parts was trying to find a way to continue building upwards despite my tower getting continually more unstable, and whenever I made a mistake it was interesting because you then have to work around it. However, once you get access to the floating blocks, this no longer happens, reducing the almost chaotic nature of building the tower. I do think that anchor points are good though as you move upwards, and instead extending the tree branches that are at the very start throughout the level could be interesting as it adds a new challenge where you are trying to figure out how to connect something way over on the other side of the screen to your structure. There could also be some variety with these too, maybe they move up and down or do something interesting that the player then has to work around.
Next, gaining the blocks felt a bit too passive for me, as if it were somewhat disconnected from actually building the tower. Even though there were boxes to collect along the way, the player will almost always receive way more boxes than the ones they collected (I think this is tied to how high you got but not entirely sure). What I would do is instead of awarding these bonus boxes automatically, instead spawn extra boxes along the player's tower at the start of each building phase. This gives the player a choice between whether they want to have less resources next round, skipping the boxes and just trying to get higher, or instead going slower, but with lots of building blocks to work with. As well, this also gives the player another challenge in trying to figure out how to get over to these boxes.
Finally, starting the player all the way at the base of their tower can get kind-of tedious eventually, for me my way up at the start was primarily a tower of the one way platforms, so jumping up them wasn't great. However, I also loved trying to jump and navigate through all the mistakes that I had made, and trying to find a way to make all of the chaos just work, so I'm not actually sure if this should be changed at all.
All in all, this is by far the best game I've played in this jam, it took me about two hours to reach the top and I absolutely loved every second of this. I wish you the best of luck in the jam, and in any future endeavours you have!