Fixed camera view
While playing a game, hold Circle + X + Start. The game will pause. Press Start to resume the game with the camera fixed at the pre-location. For the Japanese version of the game, hold Circle + X + Select.

Return to default view
To return to the default view, pause the game, then press Start to resume the game. For the Japanese version of the game, press Select instead of Start.

Alternate emblem backgrounds
Create an emblem in the "Edit Emblem" screen. Then, hold L1 + R1 + Select.

Continue from Armored Core: Project Phantasma
Insert a memory card with a saved game from Armored Core: Project Phantasma and the file should appear yellow at the loading screen. Load that file to start with the same parts and money that were obtained in that game.

Energy Shooting Machine Gun
Defeat Bibs in the Sub-Arena. This machine gun is very powerful but its ammo is a short 500 rounds.

Flame Shell
Defeat one of the earlier opponents in the Master Arena. The Flame Shell shoots a rocket that sets the enemy on fire and reduces AP slowly.

Radar-12 head
Defeat the third opponent in the Master Arena to get this head. The Radar-12 is the best head in the game but looks different.

Mine Dispenser
Successfully complete the Fromsoft Ex Arena to get a Mine Dispenser. This part shoots out floating proximity mines.

Special Rocket
Successfully complete the Guest Ex Arena to get a Special Rocket. This part shoots out a blue object that disables the opponent's FCS.

Stealth unit
Successfully complete the Master Ex Arena to get the stealth unit (back weapon). This item will take you off the radar.

Enhanced Balancer Optional part
Successfully complete the Champion Ex Arena to get the Enhanced Balancer Optional part. The Enhanced Balancer Optional part reduces recoil (the backwards motion) that occurs from firing a heavy weapon (grenade launcher, dual cannon, etc.).

New laserbalde
Get PROGTECH to sponsor you in the Sub-Arena. You will receive 50,000 credits and the new laserblade, which shoots a laserblade projectile on its own.

New laser-powered sniper rifle
Get PROGTECH to sponsor you in the Arena. You will receive 50,000 credits and the new laser sniper rifle, which does 3800 damage (more than twice that of the Karasawa laser rifle).

Bonus Ex Arenas
At the Ex Arena selection screen, you will see four sets of question marks at the bottom of the screen. These arenas are unlocked after you complete a certain requirement:

FROMSOFTWARE is unlocked after you complete all leg-specific arenas. It features a series of ACs made by From Software employees.

Guest and Champion are unlocked after you complete all of the missions (do not forget to save when prompted). Guest is an arena that contains Japanese magazine publisher's AC creations. Champion is a series of ACs made by finalists from a Armored Core: Project Phantasma Tourney held in Japan last year.

Master is unlocked when you get 100% in the overall under System. Master is an arena that has extremely dangerous ACs.

Hints:

Sword Wave
Note: Plus or Reble is required for this trick. Have a lightsword equipped, then press X, Circle while the sword is still out. If done correctly, this will fire a very powerful crescent beam that can do over 2800 AP worth of damage with the Moonlight.

Find Prize Parts in the Arena/Sub-Arena
If you have played Armored Core: Project Phantasma, you will know that you will get a free part when you defeat a certain ranking Raven. However, unlike Project Phantasma, Master Of Arena will throw more ranking Ravens at you even after you defeat all of the Ravens listed. Keep checking back in the Arena/Sub-Arena to make sure that you have fought everyone to be sure that you do not miss any prize parts.

Prizes in the Leg Specific Ex Arena
If you go into the Ex Arena, you will see that there are four arenas that are leg specific. This means that you cannot take a caterpillar (tank) style AC into the humanoid arena. The good news about these leg specific arenas is that as you conquer each one, then you will get a leg part that is from the arena type you just completed (humanoid-humanoid, four leg-four leg, reverse joint-reverse joint, caterpillar-caterpillar).

Find a FCS part
In the level that you help your MTs there are three yellow ones and six gray enemy ones. There is a building in one of the corners with columns in the front of it. Blow it up. Enter the hole under where it was located. There will be three dead ends in there, one of which can be destroyed. Search inside to find a part of an FCS.

Cavern Invasion level
There is a hole in the ceiling at the top of the first room. Fly up to it and take a left. There will be a very large room with guns mounted in the ceilings. Do not shoot at the guns. Instead, go directly to the left corner in the back, where an item will appear on the ground. This is the shoulder mounted disc shooter.

Destroy Berserk MTs level
Get past the first locked gate and find the door on the left side that follows it. Follow the corridor until you find a room full of gray crates. Do not shoot the crates or you will blow up the item. Maneuver around the crates until you find a corner with a head part on the ground.

Destroy The Giant Tank level
At the start of the mission, go directly above the tank. After reaching the top of the tank you will see a missile launcher. Destroy it immediately, then the rest will be easy.

Defeating Ultimate 9-Ball
To defeat the Ultimate 9-Ball use a combination of Large Missiles and a Karasawa.

Game Shark Codes:

Infinite AP -- D007AFD8 0168 -- 801E73B0 9C3B
Max Credits -- 8003EA74 E0FF -- 8003EA76 05F5
Infinite Rifle Ammo -- 80045480 00C8
Infinite Small Missiles Ammo -- 800454BE 0028