This is a really run idea. A puzzle, but you are inside the puzzle. I really like it And the cube is super cute.
Two things that I don't like.
The controls are really clunky. A bit of a wider camera angle, bit zoomed out, might've helped already.
It would really help if the pieces stuck together once placed correctly. It's a bit jarring to see them not really connect and all you get is the percentage going up. A bit more feedback on the connection part would really help.