The Twisted Metal III Demo from the Official PlayStation Magazine series of demo discs was meant to just be one level with Firestarter, but if you quit the game the traditional way, rather than the demo way of pressing Select, you could access the main menu of the TM3 game itself and be able to play tournament/deathmatch mode with any vehicle on all maps, and even be able to use passcodes, as well as access options and credits. The soundtrack was limited to one song and there are no cutscenes or voiceovers, but it was basically the whole game otherwise.
At present, MoshTMA has 1,319 views spread across 14 videos for Twisted Metal III, and close to 2 hours worth of content for Twisted Metal III published on his channel. This makes up 2.88% of the content that MoshTMA has uploaded to YouTube.