Hey, William. Been following Manifold on TIGSource since early 2014, back when it was still Relativity, so it's very exciting to finally play the game myself. I'm not too far in at the moment (currently wrapping my head around that red block/blue block puzzle in the green section), but it's very impressive so far.
At first, I felt the mechanic seemed kind of...derivative, not exactly the first puzzler to have you switching gravitational orientation, but it really clicked with me after two moments: 1) when you first step outside and see the scale of the world and follow the spire to the intersection point around the gate, and 2) the puzzle with the yellow block where you have to place it on another block and then walk around to the other side to grab it. That one made the whole core "every surface has its own gravity" mechanic shine
On one hand, I feel like there should be a bit more guidance on where you should go when you exit the first tutorial section, but on the other, it was a great aha moment (and a good visual signposting) to have the colored line go up the spire, inviting the player to follow it and see where it goes.
No bugs yet. And now back to that puzzle. I'm probably just missing something obvious that will make me go "of course it was that simple" when I figure it out