This game is definitely a favourite of mine. There are so many things about the game that are excellent, and only a few minor downsides.
Firstly, the components are very high quality. The game boards are covered with beautiful artwork, as are the cards and various other tokens and components. The mouse miniatures are nicely sculptured as are the enemy miniatures. My wife and I actually find it pretty scary when we have to put the spider on the table; it's so well crafted and lifelike, and it looks similar to some of a nasties we get crawling through our house.
Secondly, the game is dripping with theme. It is heavily story-based and you truly do feel like you're playing out the events of a well-written fairy tale. You never feel like putting the game away because, just like a good book, you want to find out what happens next.
Thirdly, the game play is a lot of fun. Unlike some dungeon crawl games which can be quite complex, this one has fairly simple, intuitive rules that anyone of any age can pick up quickly and easily. Being a cooperative game, you can help out younger or newer players who are a little unsure of the rules, and working together adds to the fun and the theme of the game.
There are a couple of minor let downs. There are some ambiguities in the rule book which will occasionally leave you feeling confused as to what you should do in a given situation. Also, the dice used for combat and actions are by nature quite unpredictable. If you get a string of bad rolls the game can become nearly impossible to win, similarly a string of good rolls makes it feel too easy.
However, for my wife and I the pros well and truly outweigh the cons. It's an expensive game but well worth the price tag.