I enjoyed the concept of this game, I thought it was very unique! I enjoyed the freedom to drag the numbers around the area, and I think I enjoyed having to think in 2 dimensions the most. I liked making my own numbers a lot, but I agree with @whythisname that the infinite possibilities are hard to navigate, and don't give you clues when you fail. Maybe another way to address this would be to show the player which scoring criteria they're failing? I spent a good amount of time after failing a level going through the criteria 1 by 1 to find the one I failed. Just an idea!
I enjoyed playing this game! I thought it was well done, intuitive, and easy to pick up. Great work!