It's not really browser optimised, had some loading issues and freezing when you place the first piece, as well as minor visual bugs.
I had fun messing around with it for a bit. Some of the puzzles to copy a ridiculous, you have 32 blocks to place and you can't even really tell where in terms of height and you have hardly any time to place them.
I'm happy I managed to get 100% on one of them, but it was one of the easier ones... The success drawing is cute so it was worth it :)