I got to a puzzle with three long blocks that were stacked. I thought I'd figured the puzzle out, but when I made it so all the pieces were connected, the game stuttered and then brought me back to the home menu :(
That aside, I think this is a pretty interesting game. I'll be honest, I didn't go back through all the puzzles after it reset me, so I can't say whether or not the puzzles would get more challenging, but I would hope so. It's a little weird how you can infinitely go out of bounds, at least on the main menu, but the R to restart prevents it from being a problem. I like the art and aesthetic - it's simple, and effective. The only artistic choice I'd question is the music - there's nothing wrong with it being minimalistic, but it's a bit goofy sounding, and takes me out of the game more than it puts me in.
Overall, great job!