If you've heard of this Super Mario World hack, you might know how extremely mind f*ckingly frustrating this game can be, but I just beat the main set of levels recently, I still haven't started the special levels.
I assume I'm allowed to post it since it's only an IPS (basically just a hack) that you apply to a ROM, but since I am not supplying the ROM, I'm ok, right?
Anyway here's the download for the patch, the ROM patcher and playthrough videos of the levels.
Download Kazio MarioPlay ThroughsDownload Lunar IPS
