Cheat codes for the PlayStation 2’s “Warship Gunner 2” are not available, but the game does allow for unlockable content. Included in the accessible content are a Special Mission Mode, Survival Mode and Very Hard Difficulty that require the game to be complete once on any difficulty. Additionally, players can select an Adjutant Voice and an Enemy Layout for training missions after beating the game once.
Though in-game cheat codes are unavailable, “Warship Gunner 2” has an internal work-around when it comes to research times. As the time it takes to complete research correlates to the amount of times a stage is cleared, it is possible to increase research times by completing the quickest levels repeatedly. The suggested level is the second training stage after the Japan escape, regardless of whether Admiral Tsukagi is rescued. To complete the stage at the fasted rate, it is recommended to use a ship that moves at 60 knots or better to be able to destroy the three radar stations quickly. The game also has in-game secrets, such as secret land, floating and cargo plane bases that hide parts used for certain tech upgrades and a high gravity shield that is activated after a player sinks 100 super ships.