Infinite money
At the dock screen, press Left(2), Right(2), L2, R2, R1, L1, Square, Triangle.

Speed boost
Press Up on the D-pad several times.

203mm Chain Gun
Kill 100 Aircraft as the Japanese to unlock the 203mm Chain Gun. It has the following stats: Offensive: 400, Weight: 100, Range: 3500, Ammo: 5000, only available for Battleships or Battle Carriers.

30mm CIWS
Kill 100 Aircraft as the Americans to unlock the 30mm CIWS.

356mm Chain Cannon
Kill 500 Aircraft as the Japanese to unlock the 356mm Chain Cannon.

406mm Chain Gun
Kill 999 Aircraft to unlock the 406mm Chain Gun.

46cm 60 Caliber Deck Gun
Kill 100 PT Boats to unlock the 46cm 60 Caliber Deck gun, only available for Battleships and Battle Carriers.

80cm Guided Torpedo
Kill 100 Cruisers to unlock the 80cm Guided Torpedo.

Atomic Engine Alpha
Kill 100 Destroyers to unlock the Atomic Engine Alpha.

Atomic Engine E
Kill 500 Destroyers to unlock the Atomic Engine E with the following stats: Output: 22,000, Weight 600.

Charged Particle Gun 3
Kill 100 Battleships to unlock the Charged Particle Gun 3.

Enigmatech Atli Hull
Kill 100 Submarines to unlock the Enigmatech Atli, with the following abilities: Top Speed +10%, Rudder Response +1, Control Ability +25%, Endurance +500.

Twin Hull Battleship
Kill 500 Transports to unlock a Twin Hull Battleship.

Twin Hull Cruiser
Kill 100 Transports to unlock a Twin Hull Cruiser with a 10,000 ton weight limit.

Wave Gun
Kill 100 Superships to unlock the Wave Gun. It has the following stats: Offense: 18,000, Range: 20,000, Weight: 4,000, Reload time: 1,000, Ammo: 5.

Xbattlecarrier
Kill 999 Transports to unlock the Xbattlecarrier.