During developement, devs were already creating partial assets for RC versions of two classic Twisted Metal characters: Grasshopper and Warthog. However, because developement was rushed, they could not completely finish either in time, so they came up with an idea to combine the two: they would use Grasshopper's car shape/design, stats and everything else from Warthog (including his name and cutscenes), complete with a camouflage coloration for the car and its flag. This character even became known as "Warthopper" among the devs because of this. One particular dev on the GoodrichGames YouTube channel even stated that he was disappointed with Warthog's final Special in the game (which was modified from both Specter's and Crimson Fury's) and said that if they had more time it would be fixed mechanically and also unique with each missile doing something different.

Axel was originally going to have an ending like the rest of the default characters. However, it was removed due to potential offense it may cause to both paraplegics and black people, as it has Calypso picking on the disabled driver. This may have also been the reason that he was changed from a default character to an unlockable one, as he would have been the only one who did not have an ending.

A prototype for Twisted Metal: Small Brawl has an unused 9/11 memorial screen.