"Dead Rising 2" takes place in the fictional Nevada gambling town of Fortune City. The metropolis is inspired by Las Vegas, which was wiped out in a zombie outbreak in the years between "Dead Rising" and the sequel.

Behind its cartoonish exterior and slapstick gore, “Dead Rising 2” might be the smartest, most withering piece of social criticism the game industry has to offer this fall. It’s also a heck of a lot of fun.

A lot of message-driven entertainment fails because its creators forget the “entertainment” part and get bogged down in evangelism. “Dead Rising 2” (rated M, $60 on Xbox 360 and PlayStation 3, $40 on PC) takes the opposite approach. It’s first and foremost an entertainment product, but the depravity and sinister social forces lurking behind every subplot are enough to power a scholarly dissertation.

After some setup, protagonist Chuck Greene finds himself stranded in zombie-infested Fortune City, a fictional Nevada metropolis modeled after Las Vegas. After Chuck is framed for the outbreak, he must spend the next 72 hours trying to clear his name before the military arrives, all while making sure his infected daughter Katey is administered a drug called Zombrex once a day. The drug keeps Katey, who was bitten by her infected mother, from turning into a zombie herself.

You'll collect combo cards that help you amass a goofy arsenal in "Dead Rising 2."

Like the first “Dead Rising,” the sequel takes place on a strict timeline, and players must complete tasks within specific windows to advance the plot. Miss a deadline, and you can keep playing in a doomed world, revert to your last save point or start all over with your accumulated stats and money. The unforgiving format, which only allows players to save in designated areas, divided gamers back when “Dead Rising” released in 2006, but developer Blue Castle Games has thrown critics a bone by providing three save slots. The first game only had one, so the concession allows for a bit more experimentation.

And experimentation is the first order of business in “DR2,” which virtually requires you to invest several hours in learning Fortune City’s layout, mastering the mixing of power-enhancing smoothies and discovering dozens of “MacGyver”-like combo weapons that dispatch the undead with ruthless efficiency. Just as in “Dead Rising,” the fun in the sequel is derived from the near-infinite combinations of clothing, weapons and tactics you can discover. Whether you’re slicing up zombies with a makeshift lightsaber or trying on footy pajamas, silliness is constant.

If you’re not generating enough mayhem on your own, “Dead Rising 2” allows you to team up with a friend and try clearing Chuck’s name as a duo. With the potential for gory guffaws increased exponentially by the addition of an extra player, it’s a shame “Dead Rising 2” is lacking any sort of photo mode. While it makes sense not to have Chuck, a motocross racer, carrying a camera around like the first game’s hero, a photojournalist, a screenshot-capturing mode on par with that found in Bungie Studios’ recent “Halo” games could’ve made “DR2” a darling of social networking sites.

Fans of the first "Dead Rising" will miss photography in the sequel's co-op mode.

Despite its absurd tone, “DR2” might be the most disturbingly violent game released this year. What other title encourages you to strap chainsaws to the ends of a kayak paddle and battle your way through a shopping mall, or to run over zombies with a “zomboni” machine before squirting the resulting “zombie juice” into a collector? The folks at Blue Castle are perhaps more aware than any developer in the history of video games that using zombies as a villain allows gamers to unleash a level of carnage that would be deeply disturbing if it were perpetrated against any other type of bad guy.

As much as “Dead Rising 2’s” design celebrates this fact, it also uses it as a cautionary tale. Much of the plot, and one of the game’s multiplayer modes, revolves around “Terror is Reality,” a wildly popular zombie-killing game show that requires its bloodthirsty audience to suspend its knowledge that zombies once were real people with rights and dignity. In “TiR,” contestants massacre hordes of undead, racking up points as a timer counts down. There are nine different games, ranging from the aforementioned Zomboni to Stand Up Zomedy, in which players cover the shambling undead with ridiculous props.

It’s as much a commentary on the dehumanizing nature of violent sports and modern “reality” entertainment as it is stupid fun. It’s a shame that several of the games seem prone to glitches that savvy gamers can exploit. On two separate occasions, bugs prevented me from scoring any points in Zomboni, once because my vehicle got stuck for seemingly no reason, another time because any zombies I ran over harmlessly bounced over and around my vehicle.

These minor glitches, however, along with “DR2’s” painfully long load times when you enter a new area, are worth enduring. “Dead Rising 2’s” greatest triumph isn’t visual or technical. It’s that a game riffing on the condescending, debased nature of modern entertainment is so damned satisfying. The joke’s on me, and I’m laughing my butt off.