Starxxon | Rainbow Mario And The Tubular Spiral Slide From Space 64!! @Starxxon | Uploaded February 2009 | Updated October 2024, 1 hour ago.
A simple example of what could've been done with Toad's Tool 64 version 0.6b, which was supposed to include a rudimentary .OBJ format level importer and a background swapper/importer.

Note that the Rainbow Mario effect is purely accidental.