Batman: Arkham Origins is a prequel to Batman: Arkham Asylum and is set about one year after Bruce Wayne became Batman. The main villain is the drug lord Black Mask who assigns eight powerful villains - e.g. Bane or Firefly - to assassinate Batman once and for all. During the course of the story, Batman also has to deal with Joker for the first time. It is also long before Arkham City was established and therefore Batman can explore the whole city; the new city part has about the same size as the known area. However, the different setting does not make a whole lot of difference - because of a curfew there are no civilians to be found. Batman can use the Batwing for fast traveling (there is no active flying involved) and visit his Batcave.
The basic gameplay is unchanged to Arkham City. Batman still slides through the open city and visits more linear locations in plot missions, including several boss fights. The fights use the series' trademark freeflow system: Batman takes on many enemies and quickly switches between them while building up a combo counter. An important part of these fights is to react to the enemies, e.g. using the counter-attack or using certain abilities/gadgets to counter the enemies' special attacks. When said enemies have firearms, melee fights are out of the question and Batman has to use stealth. Then he typically sits on gargoyles, observes the scene and picks out one enemy at a time. Here Batman can use his gadgets to distract/take out enemies or use the detective view to see through walls. Defeating enemies rewards experience points - more are awarded when using skills/gadgets - which are used to upgrade gadgets or improve Batman's abilities.
During the open world segments, there is a lot to do. Besides fighting even more enemies, there are side quests to solve, e.g. stopping the sniper Deadbeat or solving the Enigma puzzles which usually involve pressing switches and using gadgets. Riddler's photo challenges were removed, but in turn the crime scene investigations with detective view were expanded and involve short videos which can be searched for clues.
Besides the main story there is the challenge mode (defeating enemy waves for a highscore) and the new multiplayer mode for eight players divided in three parties: two gangster factions (three players each) and Batman & Robin which all fight between each other. While the gangsters play like in a usual third-person shooter, Batman & Robin have to use the stealth mechanics from singleplayer mode. The singleplayer part was developed by Warner Bros. Games Montreal and the multiplayer part by Splash Damage Ltd.