8 Bit Mayhem is the brainchild of some crazed Black Metal fan from the U.K. who had the idea of recording classic Black Metal songs through the soundboard of the good old Nintendo Entertainment System. The technical intricacies of NES audio are lost on me, but the results are truly a sight to see (or, rather, something to hear). One can't help but imagine what it would be like to have these tracks as the background music to Castlevania.
If you're into this sort of thing (and honestly, who isn't?), you are in luck--the band has made their debut album--cleverly entitled De Mysteriis Dom SuperNes--available for download. It bears mentioning that the above album art is actually a bit better than the artwork for the actual Mayhem's genre-defining classic.
De Mysteriis Dom SuperNes is available here: