Man, I love how you took some of the concepts of Factorio, and made it a puzzle game. There is something inherently satisfying about games involving conveyor belts that transport resources.
I have no clue how you pulled off a nice looking 3D game like that in the browser. It's pretty awesome.
I played through the entire game, and managed to 3 star every level except level 10 (completed it with 41/40 and couldn't bother to find what to optimize). The content potential this game is over the roof. With more mechanics and more levels, this definitely could be fledged out into a commercial game.
I did enjoy the complexity of the puzzles, having to figure out counting tiles and noticing the recurring patterns that will happen because of the grid and movement system (if you make the grid into a chess-colored pattern, 2 generators on the same checker color will never be able to merge their content, only if they are on 2 different colors).
I did not notice until I had finished playing that I could check the recipes (I pretty much used trial and error the entire game), so making it more obvious by adding some contextual menu could be a pro move. I also found that it was hard to predict what side the materials will go to on each turn on the switching conveyors, even by counting. Some way to easily be able to tell what will happen on each turn pair would be awesome.
I think experimentation through trial and error is a good thing for a game like this, but the issue was that every time you wanted to attempt something, it would reset the entire board, so you had to tediously remake the entire board and hope not to make a mistake. This was slightly annoying, but I managed to stay engaged in the game. If levels were bigger, I would definitely grow frustrated.
It was hard to see on transforming belts what direction the conveyor was heading. Some slight arrow or something of the kind would be a really nice quality of life addition to the game, removing a bit of trial and error.
The controls were kind of finicky, this game would definitely benefit from more polished controls, allowing to rotate a piece without deleting it (if that was possible, I had no clue how. If its possible, then maybe show the keyboard shortcuts somewhere).
I did also notice some of the floor was missing (was that intended?). The level 7 had a pretty unsatisfying solution, and the 3-star objective kinda screamed the solution.
This game was running a bit poorly on my other computer (which doesn't have a GPU card), which I kind of expected, but it was pretty smooth on my main computer.
Anyway, congrats on submitting such an awesome game to the jam!