This isn't the longest game in the world and it certainly will annoy you with its setup, but it still is a fine game that will entertain you for a good ten hours. I would certainly recommend getting it on sale, as the re-playability might not be there for most people. It is worth 75% off or so.
Entertainment-wise, I would probably pay more, if not for the setup of the game. You can't play random levels or go back in the game (Which will upset some achievement hunters that have to redo some parts). Once the story is going, you just have to follow along. Between that and the forced tutorials from this fairy that flies around on the screen, it is enough to make you say I am done, when you actually complete the game. There is no going back looking for a good way to pass time.
Still, the ride is worth it. This is a unique matching game where you have to keep this energy flowing by matching pieces and opening up paths for it to reach the end of the puzzle. These puzzles can take 5 or more minutes to complete and can be rather large and intimidating. To get through before time runs out, you get access to 4 power-ups, that can be recharged, and on board quick clearing arrow launchers, that can open up paths. Of course there are plenty of obstacles, too, like rocks and iced over pieces. The game will at first seem like cake, but it gets harder and harder as it goes.
As it gets harder, it also gets more creative. There are 64 main levels and each one is unique in various ways. They mix things up like forcing you to move fast enough to keep up with the flowing energy or to focus on getting only bonus power-ups to get past certain narrow gaps. The screen shifts to where you are supposed to focus, so you move along the giant boards as the energy does. It isn't too hard to win, but you will still lose a couple and win a few in the last 30 seconds or so, before time runs out.
In addition to the 64 levels, you also get 16 find the difference games and 4 hidden object games. None are hard and only the hidden object ones are really fun, but they offer a respectable bonus selection of mini games.
Over time you unlock magic books and information on magic creatures. It is pretty straight forward and really, you will just want to get back into the games. The interface and setup are both borderline horrid and the whole thing is just way too counter-intuitive. For example, you have to keep returning to the main page to click start, instead of doing it right from the book interface. Basically close book, then click start, which makes no sense if you are playing it.
I enjoyed it and managed to get all of the achievements in around 10 hours. I won't be going back and playing it again, but I did enjoy the play through. I'd recommend trying it out if you are bored and find it on sale.