Nearly 22 years after its release, people are still finding glitches in Mega Man 2. Case in point, this "sudden death" game breaking glitch. The glitch is activated when Mega Man and Bubble Man die simulanteously. In the following video example, a stray Buster shot takes out Bubble Man, while Mega Man meets his demise by the spiked ceiling. What happense after that? Find out below...
Upon re-spawn, you're pretty much invulnerable. The source of the video, BubblemanNsider, speculates the following:
"When a robot master's life is 0, invincibility is activated on the player, unlike in Mega Man (1) where you could die by a leftover projectile, but since invincibility was activated, it won't turn off until you get to the "get weapon" screen or start another stage. I'm not sure if this can be done on other versions of Mega Man 2, this is the NES version."
The glitch is present in both the legitimate NES cartridge and emulation. Doubtful this trick works with other Robot Masters (Bubble Man is the only one with one-hit-kill obstacles in his room), but it's worth investigating.