Serious Sam: Siberian Mayhem

Adventure· Shooter· Boomer Shooter· Action

Released Jan 2022

Serious Sam: Siberian Mayhem is a new stand-alone expansion to the world of the classic FPS series. Join the fight against Notorious Mental on a journey through the wild lands of Russia, and find your way through this lost chapter of Sam Stone's adventures.

92% positive · 5,265 reviews

Done

All announced content has been released

High confidence

Done

All announced content has been released

High confidence

Where to buy

Steam Updated 12 Oct 2026 $19.99

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Evaluation

Serious Sam: Siberian Mayhem launched on January 25, 2022 as a standalone expansion co-developed by Timelock Studio and Croteam. Following launch, the developers delivered a strong year of post-launch support: Update 1.03 (May 2, 2022) added Survival Mode with six new maps, eight new player models, and Steam Workshop/modding tools; Update 1.04 (August 1, 2022) brought additional polish and gameplay improvements; Update 1.06 (December 18, 2022) introduced a Christmas seasonal event and New Game+ mode; and the Anniversary Update 1.07 (January 25, 2023) wrapped up the year with bug fixes and polish, with the developer reflecting warmly on a completed year of support — and making no mention of any future content plans. No updates of any kind have been posted for Siberian Mayhem since January 25, 2023. A March 26, 2026 announcement confirmed that Croteam has handed the Serious Sam franchise to Behaviour Interactive for an entirely new game (Serious Sam: Shatterverse, which launched August 31, 2026), while Croteam itself is focused on The Talos Principle and a new IP. This makes clear that Croteam and Timelock Studio have concluded their work on Siberian Mayhem. The only DLC — the soundtrack — was released on February 4, 2022, and there are no unreleased DLC items or outstanding commitments. The game is complete.

Evidence

Croteam announces Serious Sam: Shatterverse under Behaviour Interactive as the next Serious Sam game, while Croteam states it is focused on The Talos Principle and a new IP — signaling that work on Siberian Mayhem has concluded.

news post · Mar 26, 2026 source development ending

high

One-year anniversary update released with bug fixes and polish. Developer reflects on a completed year of post-launch support with no mention of future content plans.

news post · Jan 25, 2023 source development ending

high

Content

1 of 1 released · no outstanding content

Released

Serious Sam: Siberian Mayhem Soundtrack

Feb 2022

Media

Details

Developer

Croteam

Publisher

Devolver Digital

Achievements

Platform

Windows

Controller

full support

Steam Deck

Playable

Players

Single-player · Multiplayer · Co-op

Boomer Shooter Action Adventure Shooter First-Person Atmospheric 3D Dark Old School Horror Sci-fi Combat FPS Linear Fantasy

About this game

Welcome back to the world of Serious Sam in 'Siberian Mayhem' - a new standalone chapter in the adventures of 'Serious' Sam Stone. Make your way through the vast Russian landscapes on a quest to catch up with the traitorous General Brand, who remains one step ahead of Sam at every turn. The road is long, and there is oh so much to see.

Co-developed by Timelock Studio and Croteam, 'Serious Sam: Siberian Mayhem' presents an expanded look at a familiar journey full of forgotten stories, unexplored places, and Sam's trademark guns-blazing battles against Mental's Horde. Join the fight, comrade!

WELCOME TO SIBERIA

...the heart of Russia. This place is huge, cold, and so unpredictable even the alien invaders feel lost. Travel through five new levels set in a beautiful and dangerous world, from Arctic coastlines and desolate forests to abandoned villages and a chilling ghost town. Siberia is large enough for you to fight & explore for as much as you want.

BEASTS OF THE APOCALYPSE

Only the strongest souls survive in Siberia, and Mental knows it well. A new set of dangerous foes and bosses join the Horde in 'Siberian Mayhem'. Including some of the most advanced and intimidating creatures you never expected to see.

TEMPERED STEEL

There's only one thing that stands between Serious Sam and his enemies - a gun. Treat yourself with a deadly arsenal of new weapons, from the legendary AK to experimental 'Perun' crossbow, and more! Do you want to cause death from above or become one with 50 tons of first-class firepower? New gadgets and vehicles are locked, loaded, and ready to fulfill your most destructive dreams.

AT HOME AMONG STRANGERS

When you think the journey is over and there are no more stories to tell, the universe gives you a second chance. Meet a gang of new outcasts and unexpected characters who will help Sam on his journey to Tunguska. Complete side-missions in order to uncover new chronicles these wild places uphold. And pay attention to your surroundings - the world itself can tell you something you never expected to hear.