Mental's forces are invading Earth, humanity's last stronghold, and there's no way to stop him. One of the heroes during these battles is Serious Sam, who constantly and ruthlessly fights off every alien he encounters.ДЄfter many battles, humanity is now doomed. His power and craziness earns him the name 'Mental'. After being woken up, Chaad Sheen manages to defeat the humans, one battle after another. He decides to go through it, which was actually an ancient alarm system for Chaad Sheen designed to wake him up as fail-safe in case he hadn't exterminated all intelligent life in the universe. While exploring Sirius, Sam 'Serious' Stone, a Captain in the Earth Defense Force, discovers a large asteroid belt surrounding the planet that was never mentioned in the old Sirian archives. Humanity ignored the Sirian's warnings about Chaad Sheen and traveled through the universe with technology based on a Sirian spaceship that was located on one of Saturn's moons the SSS Centerprice. However, they were wiped out by a mysterious being called Chaad Sheen, who apparently appeared in the universe in order to wipe out all intelligent life once every 100,000 years. This technology is from the Sirians, an extinct species that were quite similar to humans. Each monster dies in a different way.In the near future, humanity has uncovered advanced alien technology in EgyptВ which has allowed humans to travel into the farthest reaches of space. Killing monsters can now be done with your hands, and it looks graphically good. Instead of revolvers, we use a large-caliber Desert Eagle. Several guns were added from the middle of the 21st century, and instead of a saw, we were given a sledgehammer. This can only be done by one cartographer, who is sent with us and an elite squad of fighters. In addition to the fact that we have to find this artifact that launches the portal, which will later send the hero to the past, but also launch him. Sam is sent to the territory of the Pyramids, where the 'Key of Eternity' is located. Humanity actively opposed him in space, but the alien creature did not stop the pressure and decided to seize the entire Earth.

The actions of Cool Sam 3 begin 3 years after the start of the war with Mental (Tah-Uma). Sam will fight not only with God, but also with his armies.

These actions attracted the attention of Tah-Um and his countless armies, which he cloned every minute. Intergalactic flights became available, space travel became entertainment. When humans found the remnants of civilization from Sirius, their progress surpassed all expectations. In a first-person shooter with an FPS style, Serious Sam will fight against Tah-Uma - the oldest god of the cosmos and the god of a small galactic space. The materials found replaced almost all of the earth's resources. Due to the found fossils, in Serious Sam 3: BFE scientists begin to accelerate material processing, study engineering and advance science. In the middle of the twenty-first century, mankind found on the territory of Ancient Egypt the remains of another civilization that arrived from the planet Sirius. Tough Sam's story begins long before he was sent back in time.

Serious sam 3 soundtrack