The gameplay involves Rico fighting hostile militants with guns and a grappling hook, enabling players to tether objects to each other and slingshot into the air with a parachute.

[3] The map is Rico's PDA, with points of interest including mission locations, settlements, military outposts, race challenges and the player's progress.

The game features a large arsenal of weapons, from two-handed pistols to rocket launchers,[5] and a variety of sea, land and air vehicles.

Players can drive them, jump on top of them or hide in front of them while they are moving[5] and hijack enemy vehicles, triggering a series of quick-time events.

Early in the game, they encounter a black market supplier from whom weapons and vehicles can be purchased (with optional delivery to the player's location by helicopter).

[3][9] Four years after Just Cause, Rico Rodriguez is dropped into Panau to find his former handler Tom Sheldon, who is suspected of going rogue and aligning himself with the country's dictator Pandak "Baby" Panay.

With the aid of intelligence asset Karl Blaine and a weapons dealer only known as the Sloth Demon, Rico allies with the island's three dominant criminal gangs and factions: the Roaches, an organized crime syndicate; the Reapers, an insurgent socialist militia; and the Ular Boys, an ultranationalist rebel group which espouses traditionalism and opposes foreign influence.

[10] Rico gathers enough information to track down Sheldon, who reveals that he has been the Sloth Demon while he was investigating a greater conspiracy behind Panay's rise to power.

Jade later explains that the Roaches, Reapers, and Ular Boys are secretly backed by Russia, China, and Japan, respectively, to bring down Baby Panay, but Rico and Sheldon wonder what the small island has which is so attractive to superpowers.

Russia, China and Japan send a fleet of supertankers to Panau, and the U.S. begins scrambling its military forces to defend the island.

Sheldon agrees, assuring Rico that a president friendly to the U.S. will be installed on Panau and the island will be closely monitored; the group raise their glasses, toasting friendship and a job well done.

Since Just Cause's grappling hook was praised,[14] the team made it more accessible and easier to use as an essential part of the sequel's combat system.

They added the Chaos system, enhancing player freedom by allowing them to progress through the game in a number of ways instead of completing missions.

[7] The game is set in Panau, described as an island with a variety of landscapes and cultural influences (including Japan, Thailand and the Malay Archipelago).

[26] According to studio founder Christofer Sundberg, the demo was envisioned as a smaller version of the game so players could fully experience its open-ended gameplay.

[28] An Ultimate Edition, with the game and the Black Market Aerial and Boom Packs, was released on 20 December 2011 for the PlayStation Network.

The Black Market Aerial Pack included an F-33 Dragonfly jet fighter, dual parachute thrusters and a multi-lock missile launcher.

[35] Just Cause 2: Multiplayer Mod originated as a fan project by two modders, Jaxm and Trix, who were impressed with the game's scale after playing its demo.

[37][38] It supports achievements and adds multiplayer capability, allowing hundreds to thousands of players to interact in the game's map of Panau.

[40] Just Cause 2 received generally positive reviews upon release, with critics praising its gameplay, graphics and open world; the game was widely regarded as a significant improvement to its predecessor.

[46] According to Neigher, the varied landscape and the grappling hook made Just Cause 2's game world superior to those of Grand Theft Auto and Infamous.

[44] Eurogamer's Simon Parkin commended Avalanche Studios for developing a "picture-postcard amalgam of Pacific landscapes" without significant technical difficulties, such as framework instability.

[45] However, Kevin VanOrd of GameSpot and Ryan Clements of IGN noted a number of gameplay problems, such as loose shooting mechanic and technical glitches.

[44][46] Eurogamer's Parkin agreed, adding that the tool was a mix of Spider-Man and Bionic Commando, but Game Informer's Marchiafava thought that the mechanic and its precision exceeded both.

[46] VanOrd described the stunts as "satisfying", "silly", "fun" and "crazy", and stated that travelling between locations was so enjoyable that players would rarely use the black marketeer.

[48] Clements praised Avalanche Studios for providing action only found in a "top-dollar Hollywood production" with the game's stunts.

[49] Just Cause 2's story also received mixed reviews, with Neigher criticizing its mediocre voice acting and lack of logic.

[44] Clements thought the presentation of its cutscenes were not on par with the game world,[50] and Parkin described the plot as a "low-rent thriller".

In February 2014, describing its sales as "slow", studio founder Christofer Sundberg said that Just Cause 2 had sold more than six million copies.

[54] Purchasers of Just Cause 2 and another Square Enix game, Sleeping Dogs, received an exclusive Rico Rodriguez outfit and the ability to perform "stunt-style takeovers" while hijacking vehicles as Officer Shen.