Quote from the SA-forum:
Well look on the site for some basic info, but gameplay wise, think of DIABLO meets FALLOUT, with the music and characters of Sonata Arctica.
We have analysed each song, and gotten ideas and built an alternate world, one where Nuclear winter is a reality. There are various factions that exist in the world, both friend and foe.
Sonata Arctica will be providing feedback, ideas, in game voices and even new material. (in the form of a new song or two. In fact this might be one of the goals in the game, to unlock the new song - nice reward! Wink )
We are hoping to bring a rich and beautiful world to your PC soon.
We are also very aware of tie-ins or licenses that fail in many ways, but as fans of Sontata Arctica and game players ourselves, we feel that we are the ones to do justice to both fans and game players.
Our goal is to create an awesome game first, one that even non fans would be willing to play, and then making it extra special for fans...
This way we would introduce people who do not know of Sonata Arctica, to their wonderful music, and at the same time give existing fans an awesome experience.
Man.. that sounds great
I've always loved RPGs and Sonata Arctica, so the mixture of both.. Hah. 
Well, here's the website:
http://www.winterheartsguild.com
).
, besides, I don't like a lot the games but I would try this one 