First of all, thanks for this repo, the UI looks great and I had fun solving some of these puzzles :)

Would like to point out that 'Hand' has a non-unique solution - I only managed to solve it by 'guessing' how the picture looks like. The problematic section is here:
Screen Shot 2020年07月20日 at 5 22 20 PM
of which, the intended solution is:
Screen Shot 2020年07月20日 at 5 22 27 PM
However, a possible other solution (which is valid) is:
Screen Shot 2020年07月20日 at 5 22 11 PM
The latter solution, though valid, is considered wrong. Personally, recommend changing the puzzle to have a unique solution vs the UI allowing solving with multiple solutions.