First off, it's a arcade game, not rpg, so there is not much story. Second, is it really the game's fault that you hurt your arm? it's Wii's fault. All Wii games are trying to use the new controller and so by that will make you move your arm... so if you are a thumb mover, go buy a ps3/360 instead.
The game's simple to pick up and understand; press the A button or swing the remote to swing your sword and beat up the bad guys. But the game play gets repetitive (you slash through the same guys over and over again), the text driven storyline is a bore and the graphics are lacking. Another problem is the controls; they are clunky. This makes the boss fights needlessly hard.