The Day The Moon Fell is the 15th episode from Ruby-Spears' Mega Man animated series. The episode was written by Richard Merwin.
Dr. Wily steals a tachyon capacitor and uses it in his latest invention to pull the Moon closer to the Earth's surface. This results in several weather outbreaks like tornadoes, earthquakes, massive rain storms and tidal waves. But, the capacitor was actually a joint invention of Dr. Wily's and Dr. Light's from long before Proto Man, Mega Man and Roll were created, and now Mega Man has to get it back before the entire world is devastated by Dr. Wily's sickening plan.
- Dark Man 2 is the only one of the four Dark Men to appear in the cartoon.
- The Battontons make an appearance in this episode.
- This episode marks the first time ever in the history of the Mega Man series that Dr. Light and Dr. Wily are shown when they were young men and (supposedly) friends, before the creation of Proto Man.
- Dr. Light's younger self bears a resemblance to Nintendo's mascot, Mario.
- In the beginning of the episode, Proto Man is seen inside the building with Guts Man and Dark Man and then disappears and is piloting the helicopter over the building just a few seconds after he was last seen.
- Eddie has an umbrella in this episode and resembles the Rackaser enemy from Mega Man 4 when using it.
- Some of Quick Man's lines are voiced by stand-ins, despite Byrnes' consistent portrayal of Dr. Light (the line "Hey, what the!?", for instance, was spoken by Scott McNeil, and altogether lacks his 'quick-talking' gimmick).
- The end credits song in this episode is "Got Myself Together" by The Bucketheads. The Bucketheads was a moniker used by DJ Kenny Dope of Masters At Work. The song contains samples from Brass Construction's song "Movin'", which went to #1 on the Billboard Hot 100 in 1976. "Got Myself Together" went to #1 on Billboard's Dance Music/Club Play Singles chart.
- Dr. Wily: "It could pull the Mooooon out of its oorrrrbit!"
- Dark Man: "But that'll cause tidal waves!"
- Shadow Man: "Big earthquakes!"
- Quick Man: "Huge storms!"
- Dr. Wily: "Preeeeeecisely!"
- (Quick Man throws Quick Boomerang through a fake Mega Man)
- Quick Man: "Huh? How he do that?"