The level only has two main graphic edits; the SMB3 Giant Goombas have become moving platforms to help guide you across the Munchers that plague the ground, and the yellow SMW Switch Blocks were recolored to avoid clashing with the SMB3 colors.
EDIT: I made a V1.1 with a few minor fixes. The switch blocks are now SMB3-styled, and there are a few more coins. I also removed one of the Platform Goombas since it wasn't needed.