Interesting what you say about textures, on the main page there are two commercial jets with decals including text on the side. Perhaps they did add them eventually? Or are they just very high poly and still coloured individually?
No, Soji Yamakawa (the sole developer of this game) never added texture support to vehicles. Those letters you see there are entirely made out of polygons and have their own color, distinct to the rest of the plane's body. Sometimes those polygons are embedded on the plane's mesh, and others they're just floating above the fuselage. The latter technique simplifies the entire plane's topology quite a bit.
Ever since the days when early geforce displaced late 3dfx I've been wondering how computer graphics might look like if it wasn't all buried under deceptive texturing. Doubling polygon count gives laughably low visual improvement, compared to what you can achieve with clever texture fx along the lines of bump mapping, but modern polygon count capabilities should be so big that difference might well become meaningless again.
