This is one of my favourite puzzle games of all time! Adorable little characters and story; great mechanics that are elegantly & intuitively taught to you. The level map solves the main pitfall of puzzle games (i.e., the steep difficulty curve in the last few levels keeps you from finishing it). Some of these levels are HARD, but there's a main path that's very possible to complete, with a bunch of optional branches. Best of both worlds. It's all very thoughtfully designed, and great fun.