One dimension means traveling around on a level surface. Two dimensions means you can move around on the flat surface and you can move up and down. Flying in three dimensions '3D' means you can fly...
The 3D you are talking about is not actually "3D". It only means there is an aspect of depth in the game. You are still VIEWING the game in 2D. Unless of course you are VIEWING a 3D 3D game in 3D. As...