So, you say you want to do the game justice, but you want to change the music overtones with rock?!
Don't get me wrong, I'm a huge metalhead, but If you're going to do a fable fangame, please, please, PLEASE don't
change the music. If anything, I would suggest music that fits more closely to that of Hanz Zimmer or Harry Gregson-Williams.
Other than that, I think it is a good idea. Twinblade was certainly one of the cooler characters in the game.
On a side note: You should probably look at the format requirements for posting in new projects.