Serious Sam 4: Planet Badass is a first-person shooter video game developed by Croteam and published by Devolver Digital. It is the fourth main installment in the Serious Sam series and a prequel to Serious Sam 3: BFE. The game features a large open world, dynamic enemies, and a variety of weapons and vehicles.

However, some players may want to play the game offline without an activation code. This can be done by following these steps:

1. Download and install Steam on your PC.
2. Create a free Steam account or log in with your existing one.
3. Launch Steam and go to the Library tab.
4. Click on Add a Game at the bottom left corner and select Activate a Product on Steam.
5. Enter the following code: SS4-PLANET-BADASS-OFFLINE and click Next.
6. Agree to the terms and conditions and click Finish.
7. The game will be added to your library and you can download it.
8. Once the download is complete, you can launch the game from your library.
9. You can play the game offline without an activation code by selecting Offline Mode in the main menu.

Note: This code is only for personal use and not for resale or distribution. It may not work for future updates or patches of the game. It may also violate the terms of service of Steam and Devolver Digital. Use it at your own risk.

Serious Sam 4: Planet Badass is not just a shooter, but also an adventure game. The game features a variety of locations, from ancient ruins to modern cities, and a rich story that explores the origins of the Mental and the secrets of the Earth Defense Force. The game also has a co-op mode that allows up to four players to join forces and fight against hordes of enemies.

The gameplay of Serious Sam 4: Planet Badass is fast-paced, intense, and explosive. The game offers a wide range of weapons, from classic ones like the double-barreled shotgun and the minigun, to new ones like the auto shotgun and the laser rifle. The game also has a melee system that lets players use their fists, knives, chainsaws, or even enemy heads as weapons. The game also has a skill system that lets players customize their abilities and unlock new perks.

The game also boasts a new engine that allows for massive battles with thousands of enemies on screen at once. The game also has dynamic weather effects, destructible environments, and realistic physics. The game also supports mods and user-generated content, allowing players to create their own levels, weapons, enemies, and more.

Serious Sam 4: Planet Badass is not only a game, but also a tribute to the fans of the series. The game features many references and easter eggs to the previous games, as well as some surprises and secrets. The game also has a humor and personality that makes it stand out from other shooters. The game also has a soundtrack that mixes rock, metal, and orchestral music, creating a unique atmosphere.

Serious Sam 4: Planet Badass is a game that promises to deliver a thrilling and satisfying experience to both new and old fans of the series. The game is expected to be released in 2020 for PC and consoles. The game is available for pre-order on Steam and other platforms, and comes with some bonuses, such as a digital art book, a digital soundtrack, and a classic Tommy Gun weapon skin.