Looking at the video (i'd play but don't currently have an emulator set up) I can see quite a lot of decent level design and detail within the levels and like the use of different sprites that aren't actual enemies. One thing I'm not too sure on though, is the palletes of the levels themselves. I do like the colors, don't get me wrong, I just think the transitions between them are a little too harsh, examples being lotus plants and the wings on the flying platform.
Overall though, from when I watched, it looks like pretty solid and decent hack.
Super Mario: Buried Treasure