Blazing Angels: Squadrons of WWII (Xbox 360)

Unlock All Missions and Planes
On the main menu, hold L TRIGGER and R TRIGGER together while pressing X, LB, RB, Y, Y, RB, LB, X.
If you entered it correctly, there will be a click sound and you will have unlocked the entire contents of the game the naughty way. Shame on you.

God Mode (Enemy Bullets Only)
While playing, pause the game. Now hold L TRIGGER while pressing X, Y, Y, X. Then hold R TRIGGER while pressing Y, X, X, Y. If it is entered correctly, a message will appear briefly on the screen. Enter this code again to disable it, but you may as well leave it on, really. Until your mate "accidentally" resets the console...

Increased Attack Power
While playing, pause the game. Now hold L TRIGGER while pressing LB, LB, RB. Then hold R TRIGGER while pressing RB, RB, LB. If it is entered correctly, a message will appear briefly on the screen. Enter this code again to disable it.

Ace Killer Achievement
Beat all other Aces.

Ace of Aces (not Ace of Base, the three-hit-Euro-wonder band)
Get the highest score in all campaign missions.