In Co-op Battle, a team of four players max must play through unique versions of levels taken from the single-player game increased in difficulty. These levels include an increased number of enemy targets, as well as unique named enemies never seen in the original stages. Any aircraft unlocked through either DLC or single-player are available in Co-op Battle, thus allowing a group of coordinated pilots to engage the enemy with a different role (for example, player one lies an attacker to raze ground forces while player 2 flies cover with a fighter.)
Every Co-op Battle game has a time limit, which depends on the map. If time runs out, the mission will end in failure. Should a player die through the mission, 30 seconds will be deducted from the timer, while the fallen player respawns away from the battlezone.
Four Co-op maps are available.
The first map is based on mission #8, San Loma Assault, where the objective is to eliminate all targets within and around the city of San Loma. Players start in the east coast of San Loma, and begin fighting their way up the coastline to the city proper. Through the mission, players will have to assist friendly AH-64 Apache helicopters as they lay siege to the enemy, while simultaneously evading Nimbus missile fire and engaging Strigon aircraft. The mission concludes with a sea engagement against the Kraken, a unique aircraft carrier with upgraded weaponry and increased armor.
The second Co-op Battle Map is based on the ninth campaign mission, Heavy Command Cruiser. Assisted through ESM by Snake Pit, players must engage the P-1112 Aigaion and her fleet, while dealing with Nimbus attacks and massive waves of NPC aircraft.
The third co-op battle mission, available as DLC from Xbox Live Marketplace, is based on Mission #10,Ragno Fortress. Players must destroy scattered groups of air and ground targets in separate operations before one final assault on the fortress itself.
The fourth and final map, available as DLC, is based on the final mission, Chandelier. The mission is the massively powered up version of the original mission. Without any allied aircraft and ESM to assist, the players must attack and destroy the Chandelier. To get near the Chandelier, players must first face two massive Estovakian naval fleets accompanied by a large number of fighter squadrons. The ships here, like those involved in the rest of the Co-op maps, have received larger amounts of health. The ships are merciless, with the Cruisers' ESM, all ships still floating will fire their missiles at the players. The next part takes place on Antenora Crater of the Sonne Island. There are air defense weapons that must be destroyed. In this part, the Chandelier will fire directly at the crater, similar to Usea's Stonehenge. Dangerous zone will be marked on the radar. Entering this area when the railgun is firing will result in instant death. The next part takes place on the Chandelier site. There are Cruisers with ESM transmitters anchored around the Chandelier, providing both ESM and long range missiles with its VLS. In this phase, the Chandelier has a much higher firing rate than the campaign mode's version. It will constantly fire without needing to load its Stauros warheads. All targets must be destroyed first before the shielding and cooling units can be effectively attacked. The shielding panels still have two layers, but they have received the important increase in resistance to attacks. Unlike the campaign mission, the loss of a cooling unit will not reduce the Chandelier's firing rate. When all cooling units are destroyed, Strigon Team will appear. They are not required to complete the mission, so players can just ignore them and destroy the backup cooling unit, then the Chandelier's core inside the cannon itself. Both the backup cooling unit and core have strengthened significantly, they will not fall to just two missiles. For the player flying into the barrel, there will be a countdown to the Chandelier's next shot. Failing to destroy the core before the countdown ends will result in instant death.