Super Mario World for the Super Nintendo is one of those rare games that even after twenty years is still fun to sit down and play. I've lost track of the number of times I've beaten the game and it's still fun. Yet, playing the same levels over and over again does wear a bit thin after a while. That's where Lunar Magic comes in. It's a point and click hacking tool for Super Mario World that let's you change the levels, items, over-world, sprites, etc around.
Create whole new levels, add items, re-arrange the map and a whole lot more. It's a very powerful and versatile tool. Change only a level or two or go whole-hog and redesign all 96 levels. It's up to you.
The author of Lunar Magic goes by the name FuSoYa. He's been slowing adding features it it for the past ten years and it just keeps getting better and better. Pop on over to his page and download a copy today. If you create a cool Super Mario World hack with it, let me know.