Like previous entries in the franchise, in Armored Core 4 players pilot mech units called Armored Cores and take on missions in return for credits. An arena mechanic returns to allow players to fight in 1-on-1 matches against computer-controlled opponents.[1] When starting a new game, players choose from one of several Armored Cores with differing difficulty ratings. A tutorial introduces the basic game concepts prior to beginning the story sections. Once players finish the tutorial, they can begin selecting missions and earning credits for customization.[2]
Gameplay has been sped up and controls have been streamlined to be more accessible than previous entries.[3][4] Customization, a franchise staple, has retained its depth. Hundreds of available parts and weapons can be used to radically change the player's mech, and each part has a number of stats to detail its effectiveness. A change from earlier titles is that many parts are not available at the beginning of the game and instead are unlocked in groups as the game progresses in its story. Parts can also be tuned to subtly alter their performance to fit a player's needs.[5]
While system link and split-screen options return, Armored Core 4 is the first entry outside of Japan to have online multiplayer, since the mode's sole implementation in the Japanese version of Armored Core 2: Another Age. Players on the PlayStation Network or Xbox Live can play with up to 7 additional players in various deathmatch modes.[6] On the Xbox 360, Armored Core 4 introduced achievements to the franchise
