[pcwalton]

Unfortunately it's not that simple, as cool as that would be. Games generally don't expect the parts of nametables that are off screen to show up, and if you render them you'll see glitches. For example, the off-screen nametables in Super Mario Bros. contain partially unrendered parts of levels. Even for simple games like Lode Runner, the game won't draw sprites in parts of the nametable that are off screen.