Geometry Dash Tartarus is a 1.9-2.1 Extreme Demon collaboration created and hosted by Riot. It is the first Extreme Demon released in 2020.
Tartarus was originally a secret project called 'Silent Akbar', an impossible level created by Riot and many others. However, the level's impossible difficulty led to its long-term neglect.
A few years later, Riot started to improve Silent Akbar through a creative contest organized by Aurorus. So some parts were completely changed in terms of gameplay and design. Many creators, such as Hinds, EndLevel, and Komp, also participated in improving this level. As a result, the creative team decided to rename it Tartarus. On November 1, 2017, Riot uploaded the first preview of this level. After a month, Riot continued to upload a second preview. Finally, Riot officially completed Tartarus on January 27, 2018.