Battle Operation is free to play but uses an "Energy" system in which every battle costs fuel. You receive one fuel point every 2 hours, with the timer starting as soon as your free fuel is below the max. The timer can be seen in green text under the fuel counter and is read in minutes. Above the free fuel is 'stored fuel' which can sometimes be earned after leveling, stored fuel is used in the same way as free fuel but does not replenish automatically.
Mobile Suit Gundam: Battle Operation features on more realistic on foot and vehicle combat which differs from the high speed Gundam combat games such as the Gundam VS series of games. Despite needing a Japanese PSN account to download it, the game is playable on a US PSN account after downloading. However US PSN accounts are not allowed to access the real money shops.
Games can be 5v5 or 6v6. Players start off in a their mobile suits and spawn on their respective team's base. Smaller bases are scattered throughout the maps and can be used as respawn/MS request points. The main objective is to score as many points as possible for the team. The team with the highest score at the end of the timer wins. To score points you can kill enemies, capture bases, or blow up the enemy's main base by planting a bomb.
Getting points and winning matches levels players up, allowing them access to higher quality, and cost, mobile suits. Mobile Suits can be equipped with multiple weapons and accessories, although the number of accessory slots and valid weapon types vary by model. All items are received randomly, and after being received must be developed. That also happens randomly. At the end of every match three items will either be received, or will advance in development, but this can be increased by paying for a booster. The Federation and Zeon forces all have unique mobile suits, and can not use mobile suits from the other side.