Shadow Fall is set 30 years in the future after the events of Killzone 3. Helghast refugees who survived the catastrophic event known as "the Terracide" have been allowed by the ISA to live with them in a new futuristic city on the planet Vekta. The two enemies are now separated by a large heavily guarded structure known as the Wall. Taking control of ISA Shadow Marshal Lucas Kellan, your job to maintain peace between the two rival factions becomes tense as undercover operations to put an end to the war arise. Armed with an immense hatred toward the Helghast, Kellan will stop at nothing to protect his planet and put an end to the threat, even willing to sacrifice anything to do so.

Gameplay in Shadow Fall is fairly similar to previous installments, though now with more improvements. The game is much more open-ended allowing for multiple ways to reach your target and complete objectives. The player is accompanied by a companion drone called the OWL which can help you in many different ways including deploying a zip-line or stunning the enemy. Using futuristic weapons and gear allows for new stealth gameplay. The online multiplayer mode allows for up to 24-players to battle at once on any of the games default 10 maps. The level system is now challenge-based where completing any of the games many challenges will upgrade your rank. Warzone returns as an online game mode along with Team Deathmatch and Beacon Retrieval (Capture the Flag). A new feature allows for the user to create Warzones with their own specific rules and share them with the community to download and play.