Two Dimensional Frame
The game world is represented to the player visually using two dimensional graphics. The dimensionality of this representation is independent of the dimensionality of the game's world or gameplay. That is, a two dimensional camera view may be used to depict a game world with more or less than two dimensions.
Strong example Metroid [Nintendo, 1986] presents the game world to the player in two dimensions, using flat graphics that have height and width, but no depth.
Nintendo, developer (1986). Metroid. Nintendo, nintendo entertainment system edition.