What a nice little gem. The controls take some getting used to, you sing to move/fight/solve riddles. The riddles are not too hard and not too easy and the story is beautiful. You can feel that it is a game made with loads of love.
Most of the non-story achivements are done in one short chapter where you play the antagonist. Most non story achivements are rather repetitive. Wasn't a big fan of that. At least you can skip to any chapter you like, after you finished the game once, which makes the achivement cleanup easier.