Serious Sam 4 is a 2020 first-person shooter developed by Croatian studio Croteam and published by Devolver Digital. It is part of the Serious Sam series and a prequel to Serious Sam 3: BFE. The game was announced in April 2018, originally as Serious Sam 4: Planet Badass, was released in September 2020 for Microsoft Windows and Stadia, followed by PlayStation 5 and Xbox Series X/S ports in December 2021.