Thinking logically, there is a limited amount of space on a disk. Game producers fill that space, say 50/50, with one fifty being graphics, the other 50 gameplay and story. So logically, if the graphics are shitty, the gameplay can be better. (also works in reverse, if the graphics are awesome, the story can be pretty shitty *cough*CoDMW*cough*)
That's just a theory though, it could be that the game will be shit.