Not a bad little remix at all.
Never imagined these two songs could mash together so fluidly. I think the 8-bit really captures the excitement of the songs; you get sucked into the nostalgia of the GameBoy days and then BOOM! Here's some Mario to keep you guessing. The only criticism I can muster up here is I think the glissando falls you have in there every bar are a bit much; don't need to remove them, but they are overpowering and distracting from the real treat of this song.
Fantastic mash-up; keep up your good work.