- Recycled Set: Dr. Wily's castle design is entirely identical to the one in Mega Man 5.
- Screwed by the Lawyers: C&D'd by Capcom.
- The game uses a mix of custom sprites and re-done 16-bit Rockman 7 sprites for it's content
- It took only 5 months to make but had two releases spread at least a month apart - the first was a 'demo' which had everything locked out past fighting ANY of the bosses, the next was 'an official' release but you had to purchase it as a download for 10,400 Yen.
- An English Patch was being worked on by Mug-Gin Studios but has not come to fruition since the website for them went down sometime ago.
- As the game was distributed commercially (and thus, violated Capcom's copyright), copies of the game are now hard to find.
- Most of the music is original aside from Dr Wily 2, and Intro.
- Most Robot Masters are based on voted in designs held by Capricorn early in 2004, a year prior to his release of the first demo.
- Weasel Man is based on a Kamaitachi or Sickle Weasel, a magical creature similar to a Tanuki or Kitsune who created mischief for travelers.
- Waltz Man was based on a Virtual Reality program called Violinist - Virtual Music Maker / バイオリニスト-仮想音楽玩具, a freeware prevocaloid style simulator from early 2000 that would play music at random by selecting from various presets. The mask even matches one of the selectable faces to use for your own Violinist Doll.
- Puppet Man was intended to be Waltz Man's brother by default, but its odd that it isn't played up, seeing as how Death Waltz is Puppet Man's weakness.
- Rapid Man is based on a cowboy motif with the wild desert brush in the background as a setting. The catch? Its an Australian-style cowboy!
- Energy Man was based on an odd concept of using Yamato Man (a spear wielder) with a blend of Knight Man (who has armor) with Gemini Man's (who uses laser attacks) weapons.
- Laser Man is in fact a robot master based on Laserman.EXE from the Rockman.EXE Series. He even has the Laser Wave, an attack used by Laserman.EXE in the GBA games.
- The Teddy Bear Bombs were a joke based on a forum Capricorn used to visit often; he threatened that once he finished this Doujin that teddy bears might explode....
- The official box cover artwork is based on the one for Rockman Complete Works, right down to Roll using the same stance as Rock.
- The charge sound used for Roll is actually a badly re-used charge shot from Vile in Rockman X! Its also a fairly annoying sound...
Trivia / Rockmen R: Dr. Wily's Counterattack