Remember back in the early 1990s that those Mega Drive/Genesis games of Sonic started with some nasty bugs and glitches? Well, don't we all hate them?! But alas there are a number of fixes as well as gameplay improvements. Now so far Sega doesn't appear to deny sharing emulated ROMs of those Sonic Mega Drive games but you can also buy them from Steam from here:-

Thing good thing with this game is that the emulator settings allows you to enhance the picture/video quality using xBR to smooth out those eye-straining pixely staircase appearance as well as remove the No Sprite Limit to reduce the glitchy graphics artefacts. However, it doesn't solve the core bugs and glitches for those Sonic games. Luckily there are Steam Workshop mods that can add patches to those games. Now there are over hundreds of glitches that were found for Sonic 1, 2 and 3&K, but I won't go into too much depth so let's focus on the most notorious glitch of all: Super Sonic at the end of a level"

This glitch is so annoying after all that effort of trying to grab as many Rings and all 7 Chaos Emeralds, you need to...RESTART the whole game from scratch when Sonic transforms into Super Sonic but is stuck walking airborne after ending Act 1 from all levels or Act 2 from Metropolis. I bet you be furious if you had forgotten that glitch and made that daft mistake? Well not to worry, because this Workshop mod fixes those bugs as well as let you play as Knuckles!