It's good but needs some fine tuning, some puzzels are just like rotate a few degres and done and some other are actually complicated and would be fun... if it would work, most of the time i would complete the shadow really fast but it wouldn't count until i take the shadow apart and than try again (sometimes even multiple times) like i would have the complete shadow done and the bar would tell me i am cold just for me to ruin the shadow, put it back the exect way and then getting hotter...
(P.S. English ist not my first language so sorry for potential misspellings)