I think it would be cool if you could put in several different tunnel images, and if the game randomized what image each tunnel will be. I was kind of thinking of make a set of futuristic-themed advertisements.
Fog's brand dog food: For those low-gravity life-style dogs.
Perfection window cleaner: The meaner cleaner window-dirt exterminator.
Breathatol: When you need some air to breath, we provide the best! (inside joke, but not by much)
Sky travel agency: Have you been to urectum? Well, here's your chance! (Futurama joke)
Sanity-in-a-bottle: You knew someone would make it eventually.
Insanity-in-a-bottle: Nothing says rebel like a kool, refreshing main-brand kola.
Actually, I can't do graphics, but I think it would be cool if this kind of thing were possible...could I do graphics.