A nice looking game. The physics of the balls work well.
I managed to complete the first (Great Wall) game then struggled to do any others. They were too complicated. Too many curves of different angles and lengths. It needed more of a build up from easy, to medium to difficult.
Does the 'Free Drop' tutorial work? Maybe I didn't understand it.
What is the round object split into three? I assumed it was a random outlet for the ball but it didn't work (either in the puzzle section of the sandbox).
I like how you can change the style of the track.
Some pieces seemed to fit where it would be impossible in reality.
My main annoyance was the teleport. Sometimes I could pick up a piece and not be able to move. Other times I could hold a piece in each hand and move without issue.
Nearly as annoying was grabbing a piece. Often it did not highlight in blue when it was expected and I would grab at thin air a few times.