Nice pine tree, doors, etc, by the way

For the snow, I'm not sure ripples would be fine (since these are created even when the avatar stands still). Maybe simple footprints would do.
In both case, I think you should put the collision 1 unit below the actual snow, so it doesn't look like the snow is 3 millimeters deep (if you didn't have the idea already).
About your idea, Rhee, it's possible, but the avatar would "warp" each time he steps on a new face. Plus it would require re-coding the camera again, create 1 subworld and 2 regions per face (at most 6 for a cube, but for a sphere it would require an insane number). Personally I think the main part of Relativity is enough for these gravity things.
However it would be nice to see more Escher-like models in the gardens, such as a Möbius band with ants, a version of Up and Down, maybe Penrose steps...
Of course we have to forget about impossible structures...