Sort of a New Genre of Game
Apart from its hilarious plot and awesome soundtrack, Brutal Legend combines the fun simplicity of a hack n' slash with the strategy of a RTS, and to top it off it contains small doses of RPG here and there. Simply this is almost a new genre of game. Anyone trying to compare it to another game would fail because this isn't really the kind of game seen often.
Before the release of the game, people were expecting for the game to do one thing: kick ass, which it delivered in a pleasantly epic way and to top it off it's wrapped in a nice layer of metal humor and metal god appearances. Of course I can't say that this game is perfect, as most games aren't, but it certainly is one of my favorites.