Go to the main menu and HOLD both triggers and press Left, Up, Down, A, Right, B, Start then enter a code below at the cheat menu

SUPERMECH Invincibility
WEWILLWIN Get All Levels
WHERESMAX Get All models and awards
BACKSTABBER Get One shot kills
SNIPER Get One sniper shot kills
MULTIMAYHEM Unlock All multiplayer levels
FLIPSIDE Get Upside down mode
MISSMACROSS New paint schemes
MARSBASE Faster missile refresh
SPACEFOLD Fast gun pod refresh
MIRIYA Faster missile + gun pod refresh
CLEAR Cheat Codes Turned Off

Awards:
Meritorious Service (Clear Force of Arms) Unlocks Izzy Paint Scheme
Distinguished Service (Clear Enemy Within) Unlocks Rick Paint Scheme
Master Airman (Kill 100 Fighter Pods)
R.D.F. Flying Ace (Complete Master Airman Set) Unlocks Debris Field Versus Map and Max Paint Scheme
R.D.F. Starburst (Clear All Boss Missions Twice) Unlocks Flood City Versus Map
Titanium Medal of Valor (Clear Knife's Edge) Unlocks VF-1J in Story and Versus Mode
Bronze Cross (Kill 50 Battle Pods)
Silver Cross (Kill 75 Battle Pods and Complete Bronze Cross Set)
Gold Cross (Kill 100 Battle Pods and Complete Silver Cross Set)
Southern Cross (Complete Gold Cross Set) Unlocks Factory Versus Map and Armoured Valkerie in Versus Mode
Silver Shield (Clear Graveyard using VF-1A) Unlocks Graveyard Versus Map and Miriya Paint Scheme
Superior Defence (Clear Attrition) Unlocks Graystone Versus Map
Gold Nova (Clear Vengeance 3 times)
R.D.F. Supernova (Complete Gold Nova Set) Unlocks City in Space Versus Map and Patriot Paint Scheme
Robotech Marksman (Kill 50 Nousjadel-Ger in Sniper Mode) Unlocks Stealth Paint Scheme
Wolf Leader (Clear To the Death) Unlocks Wolf Paint Scheme and VF-1R in Story and Versus Mode
Tuna Head (Kill 50 Del Regults) Unlocks Queadluun-Rau for Versus Mode
Jolly Roger (Clear Party Crashers 3 times) Unlocks Skull Leader Paint Scheme
Unlocking Chapter 4 unlocks the VF-1S
Unlocking Chapter 5 unlocks FAST Packs (Super Veritechs) for Story and Versus Modes