While not endorsed by Nintendo at all, the pirate copy of Super Mario World for the NES is strikingly similar to its source material. The graphics used re-colored Super Mario World sprites, which are quite impressive on the NES. In this video Mario climbs fences and battles Bowser in the clown face copter at the end of the game. Want to see how it compares to the SNES game? Destructoid has a comparison video.