I did have my doubts at first, I thought it would be another Pokemon clone, but this even better then Pokemon in my opinion.
For starters, not all the monsters are cute and cuddly: some of them look mean, some of them look "ugly" and some of them just look so awesome! Another aspect is when you combine two monsters together you can use those monsters old abilities with your new monsters and make them even more powerful. The more monsters you combine the higher their rank goes up and the stronger they get: by the time you've completed the game, you will probably have the most unbeatable and most unstoppable team! And it's all about crushing your opponents in one single blow ;)
It's much more challenging compared to Pokemon and the story line is very good. There is a bit of level grinding and some travelling, but it's so addictive and just so much fun to play you don't really notice.
I got when it was £10, so I think it was a great bargain. Even though it's now £17.99 now that I have played it I would happily pay that price for this game.
I would happily give it 5 out of 5, but I don't think some of the level grinding is everyone cup of tea. Don't let that intimidate you, because I can guarantee that if you like Pokemon and similar games you will defiantly LOVE this game.