A series of fighting games developed for the Neo Geo by ADK. Imagine Hattori Hanzo, Kotaro Fuma, Rasputin, Joan of Arc, Genghis Kahn, Bruce Lee, Hulk Hogan, and a Nazi super-cyborg coming together and battling each other for the right to fight an alien shapeshifter bent on taking over the world. That's World Heroes in a nutshell; a one-on-one fighter built around No Celebrities Were Harmed versions of historically famous people beating the snot out of each other.While initially largely derivative of Street Fighter, which explains its complete lack of longevity, it developed some interesting gimmicks later on by Jet and Perfect. There was also a slew of Rule Of Cool involved in the character selection; the sequels added even more thinly-veiled historical personages, including characters based on Captain Kidd, Erik The Red, Joe Montana, Lu Bu and Jack The Ripper, as well as generic witch-doctor Mudman for some reason.Unfortunately, cool characters and gimmicks weren't enough to make the series stand out, and it languished into obscurity. The only appearance it made ever since was in Neo Geo Battle Coliseum, where Hanzo, Fuuma, and Mudman were playable characters.
While he does bear a strong resemblance to Marvel comics villain Blackheart, Neo-Dio is actually an Ersatz of Baoh, the protagonist of the manga of the same name, with a few traits of Dio Brando (created by the same person as Baoh) thrown in for good measure.
Simlarly, while Brocken appears to be a riff on M. Bison, he's actually based on Brocken, Jr. and Brockenman from the anime Kinnikuman, the characters Bison was also partially inspired by, along with a liberal sprinkling of Stroheim from JoJo's Bizarre Adventure.
Damn You, Muscle Memory: In the first three games, you gently press the punch or kick button for a weak attack. By pressing and holding either button, you'll execute a harder attack. The fourth game has two punch buttons and two kick buttons, plus the ability to execute stronger basic attacks by pressing both punch or kick buttons a la early Samurai Shodown games.
Death Course: One play mode in (at least) the first two games replaces the standard character-specific stages with an arena full of traps, such as landmines and electrified ring ropes.
Finishing Move: World Heroes Jet has a literal variation here—at the end of each of the first four rounds, the deciding move of each individual fight is noted. Non-character-specific normal moves are dubbed 'Standing Blow of Ba-Boom', 'Standing Kick of Chaos', 'Killer Crouch Kick' and the like.
No Celebrities Were Harmed: All the characters except Hanzo, Fuma, Captain Kidd, and Rasputin have their names changed. Jack is arguable, since he's based on Jack the Ripper, but that wasn't the guy's real name... far as we know. Mudman and Brocken, as noted above, are the only characters who aren't based on any specific figures from history. Early concepts for the game featured Brocken as a cyborg Adolf Hitler; this was dropped early in development for obvious reasons, (World Heroes, indeed), though he retains his toxic gas attack and "Heil, Brocken!" win quote in the Japanese versions of WH 2 J/WHP (text only, likely a reference to Brocken Jr.'s theme song in the Kinnikuman anime).
Many characters also got their background heavily altered. For example; Janne is the guardian of a traveling circus she grew up in, J. Carn is one of the top officers and personal bodyguard of the actual Genghis Khan and Erick is a friendly family man who himself decided to become an explorer, while the real Erik the Red was exiled for murder. Brocken, having his initial background concept dropped, does not have much of a background at all.
Brocken stars in 19YY, one of the minigames in ADK World, where it is implied that he is a flying cyborg soldier, fighting literal airships for a Reich-esque Germany in the Diesel Punk world of an Alternate Timeline. But since this game takes place inside a movie, it's probably not canon.
Zeus in World Heroes 2 Jet is very strong, but he returns as a Bonus Boss in World Heroes Perfect that you aren't required to beat. In Perfect, his moves have absolute priority and no startup, as well as being extremely overpowered. One of his super moves is a ordinary-looking punch that hits five times for 20% damage each hit. If it connects perfectly, it KOs the player regardless of how much health he/she has.
Stout Strength: Erik is probably pound-for-pound the most physically powerful character. He also has an extremely pronounced gut.
Traumatic Haircut: One of the Death Course fights takes place in a fully normal arena. However, the character portrait of the loser will be shown with all of their hair shaved.
Unicorn: Ryofu summons this one in his desperation attack. It is perhaps a Chinese unicorn.
Updated Rerelease: Subverted by World Heroes 2 Jet. The game plays nothing like the previous game aside from having the same character roster. The title was simply a jab at Capcom with its numerous Street Fighter II derivatives (specifically Street Fighter II′ Turbo).