No.Knocks said:It is indeed a NES game, not just coded to look like one. However, as a couple of people have already mentioned, Capcom probably extended the functions of the original NES, which may have included overclocking, adding more RAM, new mappers, non-standard battery, and who knows what else.
Long story short, you are unlikely to be able to emulate this beast. And I personally wouldn't want to--the Wii seems to handle it pretty well.
What's easier?
1. Develop a Nes emulator. Overclock the emulator and add more hardware. Create a Nes game that uses this extra fake hardware.
or...
2. Create a game from scratch that looks like it's 8-bit?
Heck, I even remember a interview where a member of the team said that they had to redo the sprites because they didn't look 8-bit enough, why would they do that if they made a Nes game?