Even before release, it seems the N8 will be receiving a fair amount of attention from game developers, likely due to its impressive GPU. The latest of these developers is Gameloft, who have uploaded the above video showing Asphalt 5 running on a N8. This isn't Gameloft's first hardware accelerated 3D game for touchscreen Symbian devices, as they also developed a number of games for the Omnia HD; the prior experience should help with the quality of the N8's game(s). Overall, the demo looks pretty smooth but there's no point in trying to draw a conclusion until I get to play Asphalt 5 on a N8 myself.
Also, if you didn't notice, Gameloft have used quite an old N8 prototype in this video. The prototype that they're using has an extra button to the right of the menu button.