A new patch based on SNES Super Mario World is out, and looks pretty nice:
This is a completely edited version of Super Mario World. All the levels and worlds are new, and some of the worlds have themes not present in the original, such as a water world and an ice world. Although the graphics were not changed, the game uses objects and color palettes that were not used in the original game.
The ghost houses and some of the castles have original puzzles, and all throughout the game there are hidden 1-Ups and Moons. The game is moderately challenging, and some of the last levels can get very hard.
The game is in IPS format. You need an IPS patching utility, such as Lunar IPS, to play the game.