This ad for Geometry Wars I liked. It’s almost another kind of entertaining demo, sort of:
It makes me smile and chuckle.
They’ve also got some bonkers online advertising which I can’t actually find right now. And the website is also pretty odd. In a kind of retro-kitch-gaming way: http://www.geometrywarsgalaxies.com – it’s far from being a good site, but it does a nice job of continuing the lo-fi old school vibe (I like the 3 types of navigation you can pick too).