Overtime takes place after the events of the 72 Hour Mode, unlocked by achieving Ending S where by Chuck gives Tyrone King a dose of Zombrex after he is infected when the zombies invade the Safe House and completes all cases. This mode is an extension, adding approximately another day in which Chuck must collect several items in Fortune City.
Unlike Dead Rising, it is named just "Overtime" and is not selected from the main menu as a separate mode, taking place after the credits.
Inside the Safe House, Chuck sits clueless as to what to do next. He picks up a transmission from TK, who reveals he has taken Katey and Stacey hostage, and threatens Chuck into acquiring a variety of items that he wants for unknown reasons. The list of items is as follows:
- Compromising Photo
- Gift Basket
- Expensive Champagne
- Case of Queens
- Mobile Headset
- USB Drive
- Lab Suit
These items may be collected in any order, but all must be collected within 10 game hours (the case starts at 2:00 AM, and time runs out at noon). TK watches Chuck on the monitors for his amusement. He also gives Katey a dose of Zombrex if Chuck has not finished collecting the items before 7:00 AM. After Chuck has all of the items, TK directs him to the Fortune City Arena, but when he arrives, TK stuns him with a taser-like device (possibly one of the cattle prods used by zombie handlers), rendering him unconscious.
When Chuck comes to, he discovers he is dangling from a rope upside down above the arena, which is swarming with zombies. Katey and Stacey are also tied to each other, and in the same dire situation next to him. As TK gloats in victory, Chuck turns the tables and frees himself, climbing up the rope to the central platform. Chuck frantically operates the lever to bring Stacey and Katey back up, but TK jumps him, intiating a final stand off between them.
Chuck will have to fight TK at this point, initiating the game's final boss battle. He will be stripped of all weapons/items, so the player should be sure to have full health before entering the arena. The player will keep any clothing, including DLC outfits, and will be able to choose from a limited assortment of weapons and healing items from various parts of the platform. Time for this fight is limited, since Katey and Stacey are descending slowly toward the zombie-infested arena floor.
If TK is defeated, Chuck attempts to step over his fallen body. TK gets up, and pushes Chuck against the railings on the edge of the platform. TK mumbles his signature phrase "You gotta be willing...to risk it all...if you're ever really gonna..." At that point, Chuck throws the insane TiR host from the platform to his death, completing the phrase with "win big".
At last, Chuck lifts Katey and Stacey to safety and unties them, then hugs them both and tells Katey that it's over, and they're going home. Katey, holding Chuck's hand, offers her other hand to Stacey, and the three of them leave the arena together. The camera zooms slowly away from them, and then a zombie jumps in front of the camera and screams loudly at the player for one last scare before the credits roll.
- Compromising Photo - Located in the Security Office of the Americana Casino (location of Lush-ious Lady)
- Expensive Champagne - Located in the Pub O' Gold on the Silver Strip
- Case of Queens - Located in the Underground Lab (Underground Tunnels)
- Lab Suit - Located in Roy's Mart in Royal Flush Plaza
- USB Drive - Located in the Underground Tunnels
- Mobile Headset - Located on the floor in front of the elevator in the Yucatan Casino that was used to chase after Raymond Sullivan
- Gift Basket - Located on the front desk of the Fortune City Hotel
Note: Time is limited, indicated by the mission gauges. Failure to obtain the items and reach the arena by noon will result in mission failure, and a cutscene will play showing TK lowering Katey and Stacey into the zombies while laughing hysterically. However, the ten hours alloted is ample time, as long as the player focuses on the task at hand. Indeed, even without using DLC outfits or any of the unlockable vehicles, it is possible to gather all seven items and be back at the arena in a little under three hours.
- In Dead Rising, Overtime Mode isn't named as such by any characters. In Dead Rising 2, TK verbally announces "OVERTIME" while speaking with Chuck on the Transceiver, both referencing the first game's mode, and how the ordeal is not yet over.
- TK never uses the objects that Chuck had to retreive, so it is believed that they only added this for it to relate to DR1's OVERTIME Mode. This could have also been done to keep Chuck busy while TK gets the TiR arena set up for him.
- There are two other reasons why TK ordered Chuck to get the assorted items - the Champagne Bottle and Gift Basket are probably to accomodate TK's greedy lifestyle, but the rest all relate to Phenotrans, implying TK was desperate to clean whatever evidence he could of the company's involvement, and get back in their proverbial "good books" after his failed casino robbery jeapordized Phenotrans' operation in Fortune City.