Hi Marcus, Thanks for the kind words! The answer to your question may surprise you: we pretty much just round all transforms to the nearest integer. This is done every frame. Pretty inefficient but in practice real simple and more than fast enough.
EDIT: Oh and we render the game at the low Nokia resolution to a render target and upscale it in the final scene. This also allowed us to work in black and white with a final colour filter for the Nokia colours.