Good game!
This is a nice take with a simple addition that goes a long way for a scaling type of game. The addition of "matter" and being able to relocate it into different objects is very cool, and opens up a lot of interesting puzzle and platforming gameplay mechanics!
I was a bit disappointed to see that this was a physics based game, since I think a lot of puzzle games using physics engines for the solution can often lead to solutions that are known, but hard to get to because you need to sometimes fight the engine to get it to do what you want. I usually prefer having puzzle elements like this be more un-changing in nature, in that you will get the same result every time despite minor changes. But, despite that, this one honestly worked very well. Nearly every time I launched a box across to hit a plate, it did do what I wanted. The only "janky-ness" I felt was that boxes moved underneath you when you walked over them. But this also did help me get boxes stuck out of corners, so it had a benefit to it as well.
Having to think about your matter stored, making sure you get enough or can reach certain objects to store it until you need it later was very interesting. I think the level that explored it the most was the galaxy style one with all of the purple circles. I kind of wish there were more levels about figuring out how to get a certain amount of matter across a level, or needing to manage it very resourcefully. Maybe having some object you need to grow at the end of a level, and needing to feed some central object a lot of matter so you can access it when you are near the end of the level. I think this is the most unique idea of this game, so it could be explored a bit more.
I do like how you can scale things (seemingly?) infinitely, and you do let the player scale some stuff up to a pretty large degree, which is always fun. And the feature of where items just pop out of existence is very satisfying to do to items you no longer need.
I loved the visual theme of this game, it was very simple but all of the style went together. The sounds were a bit interesting though, with some default Minecraft sounds in there, and the landing sounds felt a bit off for the theme.
Having a little info test room is also a fun thing to give to the player for a mechanic that is, is nature, fun to play around with. You just need to give us a bomb in there ;)
Nice job!