First of all thanks for the demo. As I mentioned in other comments there's still a few issues with the screen and dimensions but you're getting there.
The puzzles had some good ideas and there is a good uses of the assets you created to weave different scenarios so far.
If I can bring some criticism, I'd say dying in the game felt unexpected. It was for the 3rd door in the hub, being suddenly crushed just felt like a cheat. I didn't expect it, and so I had no reason to try and avoid it.
It's a bit annoying by the way when you die or have to reset the whole room and having to redo steps. I know theses are short but still. Especially since some room ask you to do stuff in a very specific order so it's easy to soft be locked out of the solution with the only option to reset. I feel like it should be easier to get back on a mistake and retrace your steps.
I also feel like there's a problem with distinguishing levels. First, in the hub, if you decide to do a room later, I feel like with a more complete game it would be good to know which room is which. Otherwise you just see a bunch of doors and would nor remember which one leads to what. I think on that note the game would benefit from being more visually distinct. Having visual elements that distinguish levels, make them more themed and stuff would be good. And while I know it's just a short demo, having a basic kind of narration, you know just having an idea of who your character is, where they are, why they are collecting stuff, having like a structure with long and short term objectives would be good. Or make it part of a mystery you would solve as the game progress. It gives the player a motivation to continue and makes them want to see more, something to look forward for, create a sense of progression, etc etc. It would also probably drive you to make creative levels that can tell a bit of story while also being fun to play.