I wanted to make this.
I thought of doing something like this. You can do to if you like, sharing ideas is fun. :)
I also tried redrawing Nyan Cat and then tried importing into Super Mario World.
This wasn't so hard.
Oh and the Dark World music from Zelda was I think this one custom music of the Dark World with instruments and one person edit them and send it to me a while back.
I still am maybe planning to upload this Super Mario 64 level mod, I may also show part of inside the Ancient Castle.