Many gamers recognized the title of The King of Fighters game as fighting games. But actually, there were many spin-offs based on KoF, for example: The King of Fighters Online.
Promising 3d open world MMO with legendary KoF fighters around
Kof Online by UnoTechnology
Developed by UnoTechnology in 2003. An online game based on The King of Fighters, with its dozens of colorful characters and deep mythology for a fighting game, sounds great, at least on paper. The game promised to keep an arcade-feel to the combat, while still incorporating all the standard MMO elements like levelups, item management and party functions. The only playable characters during the beta were Kyo, Athena, Leona and Kim Jaehoon, but promo screenshots also showed Iori Yagami and Kula. UnoTechnology went as far as testing their version in an open beta starting April 2003, but it was already shut down in August the same year and then just disappeared.
Kof Online by Dragonfly/Tripple -A
Sidescrolling genre of the legendary King of Fighters
The game was to be developed as a sidescrolling brawler by a Korean studio called Triple-A, but due to differences between the involved parties, Dragonfly eventually pulled the rug from under their feet and internalized the development, scrapping the existing concept and starting again. The game was still kind of being worked in 2012, but it appeared to be a low priority to Dragonfly, and there have been no big news since the initial screenshots and trailer video from 2009.
Reminds you of something, right?
Iori Yagami in action
KOF Sky Stage is an arcade vertical danmaku shooting game with King of Fighters characters released for arcade in January 2010, and also available for XboxLive. In order to rescue fighters trapped in Orochi's dimensional prison, these heroes have been given the ability to fly through the skies by Chizuru Kagura the Mirror Guardian and use their abilities to shoot down various demons and wraiths.
Hmm..an online concept about fighting games rarely succeeds and often more it needs to stay in its original format of Versus. than being adapted into an MMO.
Agreed, moreover turning the genre itself will sometimes never end better. The first online KoF in 2003, I saw the article in game magazine long long ago with screenshots, but then I didn't see any from it anymore.
To see Korean MMO developers took interest in KoF series, well I guess the popularity there were quite larger.
You forgot Beast Buster featuring KoF for android platform.
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Imma gonna edit again later and add few things, thanks.