This sounds like...
you got the midi of the song and used the bitcrusher filter on garage band to make it sound 8-bit.
Good times, mate. Gooooood times. Well made.
I have the game so I can say with authority that nothing beats the original, but I like this one. It paints a picture of Isaac and co. being pulled into a rift filled with many colors to fight a beholder or something.
Please contact me if you would like to use this in a project. We can discuss the details.