History of video games/Fourth generation of video game consoles

Improved hardware
During this generation pixel art in games becomes more much more advanced, often adopting the pointillism art style to the medium to great effect. Sprite based 2D graphics were essentially a solved problem by this generation, which lead to companies to look for ways to differentiate their graphics.

Game consoles also began using pre-rendered 3D Graphics and graphical techniques to give the impression of real 3D graphics running on hardware. Games using simple real time 3D polygons became popular, though they often required enhancement chips to draw just a few hundred polygons a second.

This generation audio improved drastically, with much more advanced audio systems.

CD capable consoles
This generation some companies attempted to release high end consoles with built in CD support, while others tried to launch CD add ons. Both strategies saw lukewarm adoption at best. CD-ROM technology was appealing because they could be used to add recorded video to games, recorded soundtracks, and other features. Furthermore, a high capacity CD-ROM was much cheaper to make ($2 for disk and packaging in 1993) compared to cartridges which held far less and cost far more. As a result CD based games saved significant amounts of money for developers. The high lead times and cost of cartridges also lead to financial issues for companies who overproduced games they were unable to sell, further enhancing the appeal of CD-ROMs as a format to some developers.

Yet CD-ROMs in consoles were not a fully ready technology this generation. Game Developers often used the extra space for enhanced graphics or audio, but often did not use the extra space to further gameplay in a way that could not be done on a cartridge. CD-ROM drives were still quite expensive, despite rapidly declining prices. They were also quite slow compared to cartridges, with long loading times compared to the near instant access allowed by a cartridge.