Turns out, the gamification of it. You can see only five pieces at a time, they're often very obscure (which would be good), in order to progress you must solve these puzzles very fast and without a single mistake. This often means restarting a level until it's possible or until you've memorised the exact position of all pieces.

I find it ironic that of all the games I play (which includes a fair few action games like Shadows of Mordor) this is the one where physical restrictions (inability to hold down the mouse button and move the mouse with precision for long stretches of time until I have found the right spot for a piece) lose me points/mess up levels most often. Instead of fun, I found this game stressful.

A more relaxed version than it's predecessor. A great buy

I really like this style of puzzle games and the fact that its Alice in Wonderland themed is even better.