I love it, and have some feedback of you’re interested:

• As your puzzle grows, the area onto which you drag your shapes shrinks. This means that there’s comes a point where your finger is obstructing the shape and target completely. There were many frustrating moments where I got the placement wrong because I couldn’t see what I was doing.
  • Suggestion: an zoom feature when placing a tile when things are at a given scale, or maybe allowing the puzzle to expand off screen and slide around?
• When the above happened, I was surprised that there’s wasn’t an undo button.
• Some music and sound effects would be nice. Something chill, like this would be nice.
• A confirmation when hitting the “back” button would be good when doing so would exit the game as well. I lost a rather impressive build out 'cause my finger slipped and it exited the game, wiping everything.