The birth of the First-Person Shooter genre was one of the biggest and most important steps in the development of modern computer games, on par with the creation of Elite, Tetris, Civilisation and Sim City. While many games had utilised the first-person viewpoint over the years with varying levels of success (always hampered by the immature technology of the time), it was Wolfenstein 3D that first showed that a game of this type could provide a decent control method and open up new, unexplored areas of gameplay that would have been impossible in a traditional two-dimensional flat plane.

Doom, with its depth-based shading, textured floors and ceilings and non-orthagonal walls "filled in the gaps" and became a touchstone for its compelling, fast gameplay and visual splendour. More advances followed, spurring the development of more and more powerful graphics cards.

Freedom of movement is integral to the success of FPS games, and has led to the genre sprouting off in new directions such as the action-RPG Deus Ex, the stealthy Thief and the strategic CounterStrike.

Targetting games such as the seminal Operation Wolf, Duck Hunt and Time Crisis don't, in my opinion, fall into the category of FPS's. In my mind, the "shooter" element is an extension of scrolling shooters such as R-Type, Ikari Warriors and Contra rather than the coordination and reflex test of a shooting range.