Mega Man 3

In hard man's stage, there are bees that drop big nests on you, this glitch gets rid of them. When the bee appears, change direction, go until the bee is out of view. Then go back, the bee is gone!
a very stupid thing to do (bug) - you know that bit in the gemini man stage where you run into break man, who blows up a passage leading to the underground? well, ok. run along the level until the screen stops scrolling. now, hold right on controller 2 (prepare to do a super jump). now, do a slide into the bit with breakman, and -immediately- do a super jump into the passage. you should fall right through the barrier and into the underground, where you may find a few things are screwed up now ...