Mega Man 3 Super Jump
What seems like an unfair trick to implement for a fairly beatable game actually intensified the gaming experience in Mega Man 3 by making it more challenging. For instance, enabling the Super Jump code added to the difficulty, making it impossible to get through those tight-squeezed sections of flooded ceilings and floor spikes. There was no advancing in the Needle Man level. Amusingly, the cheat also had the Blue Bomber walking across bottomless pits without dying. That’s what you call a favorable glitch.