3d vs 2d games

2D games are typically Scrollers. The first Super Mario Bros. on NES fits one type of Scroller ( you can't move backwards in that unfortunately). Your avatar is flat. You can move left, right, up, and down. There are several types of 2D games,.. several styles. So beyond that flat avatar and those directions of movement, it is hard to find any other constant. A 3D game usually suggest the incorporation of Depth. If you were to look into details on the Dimensions, Depth is the third Dimension. So the term holds up in reality as well. 3D basically just means it has more than 2 dimensions. COD and Skyrim are 3D because you can see more than one side of them. (You can see their faces, bodies, etc.) 3D can also be used for a 3D movie but it can also mean what I just said. And extreme gaming, just means you get a game(s) and no life it for a while, playing it for most of your time.