As a grand master puzzler I will say this simulated experience certainty reaches for the prestigious title of best simulated competitive puzzling game but it's shortcomings are plentiful.

You can't even do a full rotation on spin-form! Pretty ludicrous. Otherwise you do have the option to upload your own pictures into the game, for a limited amount of free times, which might deter up and coming prodigies within the puzzling realm since they often find it entertaining to display their own produced content as a backdrop whilst practicing the sport.

Size quantities are plenty for most. I'd wish for an even larger option, or as we call it pic sizes (pieces).

Anyways it is a good free option. I recommend real world experience so you may grow wise within facing a player and having the physical grasp of a pic, but hey puzzlers do what reject pieces do not!