The "Adventure Island" video game series is a series of platform arction arcade games, including games on the NES, Game Boy, Super Nintendo, TurboGrafx-16, and Wii Wiiware. It started out as a graphical alternative to the first game in the SEGA franchise "Wonder Boy". As Hudson (owners of the code) didn't own the franchise Wonder Boy, when they sold the game to Nintendo, the graphics were changed, and so was the name. However, this change spawned its own series.
Thus, the first game is both Adventure Island I and Wonder Boy I, but Adventure Island II and onwards are not part of the Wonder Boy series.
Adventure Island II (1991)
Super Adventure Island (1992)
New Adventure Island (1992)
Adventure Island 3 (1992)
Takahashi Meijin no Boukenjima IV (1994)
Super Adventure Island II (1995)
Adventure Island: The Beginning (2009)