The player-character receives elemental powers and superpowers that greatly increase their jump height and running speed, such that the player can hop over buildings and outrun vehicles. The elemental powers include abilities to shoot fire and ice projectiles, telekinetically toss things, and create shockwaves upon landing jumps. As the player progresses through the game, they can optionally upgrade their abilities and weapons skill tree by using collectible "data clusters" scattered around town. If the player becomes too rowdy, the alien race's police analogue will intervene. As in previous games, the player-character's look and feel is entirely customizable via a robust character editor feature.
The game is set in a nearly identical simulation of Steelport, the fictional city setting from Saints Row: The Third, though individual story missions have new, custom-designed levels. Saints Row IV's story parodies science fiction video games, especially Mass Effect 2, as well as films like The Matrix and Zero Dark Thirty, and other "nerd culture". Some story missions are propelled by individual characters' existential crises, as each Saint character is stuck in a personal simulation of their own hell, and must be rescued by the player. Other elements borrowed from video game culture include BioWare-style character romances games and a Metal Gear-style mission with an unhelpful partner.
City districts are "liberated" from alien occupation as the player completes side missions in occupied districts. Liberated districts increase the player's hourly income, which can be spent on weapons, skills, and perks. Side missions include Insurance Fraud (where the player jumps into traffic to collect insurance money), demolition derby-style Mayhem, and superpowered foot races. Saints Row IV has a two-player cooperative mode.
Synopsis
Plot
A few months after the events of Saints Row: The Third, The Boss, Shaundi and Pierce Washington are called upon to assist MI-6 agent Asha Odekar and former Deckers leader Matt Miller in infiltrating a Middle Eastern compound to assassinate former STAG leader Cyrus Temple and prevent a nuclear missile strike against Washington D.C. The Boss kills Cyrus but is unable to stop him from launching the missile. The Boss climbs aboard the nuke and disarms it before it reaches Washington, earning the adoration of America.
Five years later, the Boss has been elected President of the United States, with the other members of the Saints, Keith David and former Vice Kings leader Benjamin King acting as their cabinet. While preparing for a press conference, the Boss is told that Asha and Matt have arrived at the White House to warn them of what they suspect is an impending alien invasion. Just as the Boss is informed, the invasion begins spearheaded by the alien warlord Zinyak, who captures the entire cabinet including the Boss.
The Boss wakes up in a 1950s sitcom set in the city of Pleasantville, devoid of violence and foul language. The Saints' computer hacking specialist, Kinzie Kensington, contacts the Boss and informs them that they are trapped inside a simulation, with each of the Zin's prisoners trapped inside personal simulations of their own fears to help break their will. With Kinzie's help, the Boss breaks free of the simulation and joins Kinzie and Keith in a stolen Zin ship.
While the trio attempt to contact reinforcements from Earth, Zinyak atomizes the planet, killing everyone not already captured by the Zin including Oleg Kirrlov, Josh Birk, Zimos, and Viola DeWynter. Enraged, the Boss returns to the Steelport simulation to find their friends and reach Zinyak. The Boss rescues another prisoner of Zinyak, an artificial intelligence later named CID, and provides him with a physical body. In return, CID helps the Boss go into the other Saints' simulations and rescue them from their nightmares.
As the Saints begin to weaken the simulation, Zinyak floods it with copies of gang members the Boss has faced in the past. After Kinzie determines that the copies are being made from someone's memory, the Boss concludes that Johnny Gat, who was seemingly killed during the events of Saints Row: The Third, is still alive and trapped within the simulation. Despite protests from Kinzie and Matt that rescuing Johnny will reveal their location to Zinyak, the Boss rescues Johnny from his nightmare of Aisha's death and gets him back to the ship. Johnny explains that during the fight in which he was presumed killed by former Morningstar leader Philippe Loren he was actually abducted by Zinyak years in advance of their invasion, who concluded that Johnny could have single-handedly stopped him if left on Earth.
The Saints rally inside the simulation to confront Zinyak, but are ambushed by an enormous Zin force. They escape, but Kinzie is captured by Zinyak and the Boss emerges from the simulation to find that Keith betrayed the Saints and fled. Returning to Steelport, the Boss finds Keith has been declared president of the simulation. When confronted, Keith claims that Zinyak has the means to restore Earth, and has agreed to do so in exchange for the Boss' life. The Boss, determined to find Kinzie, pursues Keith into his nightmare with help from Roddy Piper. Keith reveals Kinzie's location and rejoins the Saints.
After the Boss rescues Kinzie from her nightmare she devises a plan to crash the simulation and weaken the Zin ship, thus creating an opening for the Saints to enter. The remaining Saints work together to overload the simulation, shutting it down just as the Boss escapes. Assaulting Zinyak's ship, the Boss finds power armor emulating the powers they had in the simulation and confronts Zinyak in his throne room. While the entire Zin Empire watches, Zinyak and the Boss battle each other. With help from the Saints, the Boss kills Zinyak by tearing his head off and emerges victorious. Impressed, the Zin surrenders to the Boss, who becomes the new head of the Zin Empire.
The Boss asks Zinyak's main servant, Zinjai, if Zinyak's claims that Earth could be restored were true. Zinjai says they cannot restore Earth as it was atomized but can use time-travel technology to return to Earth, explaining that Zinyak had used this technology to collect his favorite historical figures and kept them in suspended animation. The Boss looks at the Saints and says, "Let's go on a field trip." In a post-credits scene, the nineteenth-century writer Jane Austen, whom the Boss is a fan of, is woken out of her stasis and revealed as the narrator of the story.
If all of the loyalty missions have not been completed, an alternate ending occurs which sees the Saints make plans to take over more planets, unaware of their ability to use time travel.
