According to producer Jon Williams, Rilla Roo was created due to the game needing an eighth playable character, with the team coming up with the idea of a kangaroo. One of the first concepts for this role was a female character named "Kanga-Soo", but this was rejected by fellow producer Mark Cerny due to concerns about beating up a female character, and didn't make it past the modeling stage. According to artist Steve Bamford, the developers felt they needed "another Dingodile hybrid", spurring the creation of a different kangaroo named "Kangorilla", whose name was changed to "Rilla Roo" per the request of Sony due to trademark concerns.

In the Japanese version, a short epilogue was added for each of the characters in the credits.

The Space Bash mini-game arena is a based on the levels "Future Frenzy" and "Gone Tomorrow" from Crash Bandicoot 3: Warped. The background music is also a remix of these two levels' themes.

Demos of the game, found on demo discs and Spyro: Year of the Dragon, contain full versions of the game. The rest of the game besides the demo content is simply locked, but can be accessed through the use of a cheat code. There are many differences between the game's demo release and the final retail game.

In the Japanese version of Crash Bash, in Battle or Tournament mode, hold down R1, R2, Left and Down at the same time on the character select screen will unlock Fake Crash as a playable character. According to producer Jon Williams, the developers had been told at the start of development that the Japanese version of the game would have to be different from the NTSC and PAL versions. Fake Crash was one several things implemented into the Japanese version based on information provided to them by Sony and Universal, who Williams presumed wanted to retain the "Japanese Only" elements of Crash Bandicoot.