Has anyone played it? I put in a few hours recently on the Wii. It's spectacular. If you find yourself longing for the good old days of the NES, this game is for you. It's very much a game that could have been an actual NES game--one that would have been forever on your top-ten list.
Edit: BTW, other versions exist. There used to be a free version available for the PC. Dunno if that remains the case since the game was commercialized. But if you have a Wii, that's an enjoyable way to play it. It's a downloadable Wiiware game.