Sift Heads Rush, formerly Sift Heads Cartels: Act 4 or Sift Heads Cartels 4, is an upcoming Sift Heads Cartels game that was teased by Gamesfree.ca (Pyrozen), at the beginning of 2017, the creator posted on Facebook that "it's coming soon", however, it isn't out yet. Despite a uncertain history, the game has been confirmed in production and the script for the game has been completed. The game is not the seperate title but feature of the remastered version of the Cartels series in Sift Heads: Reborn. Chris Martin, the producer, said that the duration of Rush will exceed all chapters of Sift heads reborn. Rush will also bring the Cartels series to a successful close.
Originally, Rush would have been released on Steam on December 26,2022 under the name Cartels 4. However, pyrozen postponed the 2024 until July 4 and renamed it Sift Heads Rush. Patreon members can experience the game in advance on June 22. Pyrozen says the reason for the name change is that the game is different from previous Cartels, and Rush is more of a fast-paced game. Also, the title is a reference to Amon Rush, a drug smuggled as antagonist. On 2024 February 17, Pyrozen released a new trailer for Rush.