GTA had four different demo versions (8bit, 24bit, 3DFX nd 3DFX special) released. Unlike the final game, the demos can still be downloaded from R*'s website as of 17/07/2016: - GTA 8bit (http://www.rockstargames.com/gta/demos/gta8.zip) - GTA 24bit (http://www.rockstargames.com/gta/demos/gta24.zip) - GTA 3DFX (http://www.rockstargames.com/gta/demos/gta3dfx.zip) - GTA 3DFX Special (http://www.rockstargames.com/gta/demos/gtaects.zip)
Below is the original text from the official GTA website:
"We now have not one, not two, not three, but four GTA demos for you to choose from, depending on the graphics capability of your machine. There is an 8 bit demo, a 24 bit demo and a 3DFX demo, all offering you the chance to have a little taste of Grand Theft Auto, completely free. Just click on the icon of the demo you would like, tell your machine where to save the demo, and let the downloading commence. All these demos are set in Liberty City.
We also have a new demo available only for people with 3D FX cards, with special missions, set in the city of San Andreas. This demo is only available for 3D FX, and has not been previously released.
If you already have a copy of the GTA demo that you downloaded from another site, then we cannot guarantee that it is the best demo available. Several of the demos available are unfinished, while others lack elements of gameplay to comply with classification standards. Our demos are, needless to say, the REAL shit. You must be over 18 to download a copy of one of these demos."
Sources: Rockstar Games