Open world
There is no consensus on what the earliest open world game is, due to differing definitions of how large or open a world needs to be. Ars Technica traces the concept back to the free-roaming exploration of 1976 text adventure game "Colossal Cave Adventure", which inspired the free-roaming exploration of "Adventure" (1980), but notes that it wasn't until 1984 that what "we now know as open-world gaming" took on a "definite shape" with 1984 space simulator "Elite", considered a pioneer of the open world; Gamasutra argues that its open-ended sandbox style is rooted in flight simulators, such as SubLOGIC's "Flight Simulator" (1979/1980), noting most flight sims "offer a 'free flight' mode that allows players to simply pilot the aircraft and explore the virtual world". Others trace the concept back to 1981 CRPG "", which had a free-roaming overworld map inspired by tabletop RPG "Dungeons & Dragons". The overworld maps of the first five "Ultima" games, released up to 1988, lacked a single, unified scale, with towns and other places represented as icons; this style was adopted by the first three "Dragon Quest" games, released from 1986 to 1988 in Japan.
Platform game
The first attempts to bring platform games into 3D used 2D graphics and an isometric perspective. These games are nearly as old as the genre itself, one of the earliest examples being Sega's "Congo Bongo" in 1983. The first platformers to simulate a 3D perspective and moving camera emerged in the early-mid-1980s. An early example of this was Konami's platform game "Antarctic Adventure", where the player controls a penguin in a forward-scrolling third-person perspective while having to jump over pits and obstacles. Originally released in 1983 for the MSX computer, it was subsequently ported to various platforms the following year, including an arcade version, NES, and ColecoVision.