A longplay for Sonic 1 hack is Sonic 1337.
Sonic 1337 (distributed as Sonic Ultima 1337 in the GoodGen ROMset) is a parody hack of Sonic the Hedgehog for the Sega Mega Drive/Genesis by Ultima. Created at a time when palette-only hacks were common (but seen as technically lazy and/or sloppy), 1337 took up the valiant cause of attempting to be the “worst hack ever.” It utilizes clashing palettes (almost every zone features some form of fuchsia pink and light green), poor collision, and incorrect level layout/object positioning. Amusingly, only the level select features a correct palette.
Download: http://info.sonicretro.org/Sonic_1337