You are correct, but when you look at it this way, Wolf 3D was actually 2D: you couldn't move up or down.
If, instead of defining the number of dimensions according to the degrees of freedom in movement, we instead define them according to the visual appearance of the space in which the game is played, then Wolf 3D was 3D, this game is 1D, and a game with more than 1 pixel would be 2D.
If, instead of defining the number of dimensions according to the degrees of freedom in movement, we instead define them according to the visual appearance of the space in which the game is played, then Wolf 3D was 3D, this game is 1D, and a game with more than 1 pixel would be 2D.