Different Styles:
Hold L2 + R2 and use X to select a MS. This will give you a different style of MS 
 
Unlockable List:
Access Simulator mission 6: Unlock all characters. 
Char Aznable: Get S Rank in Simulation Program 1 after beating the game once. 
Garma Zabi: Get an S Rank in Simulation Program 2. 
LC Garret Schmitzer: Beat the game once. 
RX-78-6 Mudrock gundam: Beat the game and complete Simulator missions 27 
through 31 with A or S ranks. 
Sayla Mass and Amuro in RX-78-2 Gundam: Beat the game. 
 

  Game Shark Codez: 
 
 Master Code (Must Be On):
 0E3C7DF2 1853E59E
 EE8D117A BCCAB6C2
 
 Unlock All Pilots:
 DEADBF86 BDAA9C84
 DEADBF82 BDAA9C84
 DEADBF8E BDAA9C84
 DEADBF8A BDAA9C84
 DEADBF96 BDAA9C84
 
 Unlock All Simulations [Note]:
 DEABC3AA BFAC9E86
 DEABC3B6 BFAC9E86
 DEABC3B2 BFAC9E86
 DEABC3BE BFAC9E86
 DEABC3BA BFAC9E86
 DEABC346 BFAC9E86
 DEABC342 BFAC9E86
 DEABC34E BFAC9E86
 DEABC34A BFAC9E86
 DEABC356 BFAC9E86
 
 All Missions Rank S [Note]:
 DEABC242 BDAA9C84
 DEABC24E BDAA9C84
 DEABC24A BDAA9C84
 DEABC256 BDAA9C84
 
 All Simulations Rank S [Note]:
 DEABC086 BDAA9C84
 DEABC082 BDAA9C84
 DEABC08E BDAA9C84
 DEABC08A BDAA9C84
 DEABC096 BDAA9C84
 DEABC092 BDAA9C84
 DEABC09E BDAA9C84
 DEABC09A BDAA9C84
 DEABC0A6 BDAA9C84
 DEABC0A2 BDAA9C84
 
 
 
 
 Note: You may have to start a new game for these codes to work.