Ace Combat: Operation Katina is the arcade mode version of the game puts the player in control of Ace Combat 04's pilot "Mobius 1," the legendary Ace fighter pilot who brought the ISAF to victory singlehandedly. The player's mission is to play through a number of stages filled with enemies and defeat a certain number of them in order to advance to the next stage. As the player progresses the game naturally gets more difficult and the player will have to adopt new techniques for countering the increasingly aggressive enemies' attacks. The mini-game is split into four branches, levels 1-4: 1 being the least difficult and 4 the most challenging. "SkyEye", the AWACS from Ace Combat 04 returns as well and provides mission support for the duration of the game.