Deadly Skies cheats and cheat codes for Playstation

Stage select
Press L2, L1, Triangle, Up at the title screen.

Start at Boss level in 2 player mode
Press L2, L1, Square, Up at the versus mode selection screen.

Start at 2nd Boss level in 2 player mode
Press L2, L1, Square, Down at the versus mode selection screen.

Unlock F-117
Press Square, R1, R2, Square, Up, Square, L2 at the plane selection screen. 

Unlock F-19
Press Up, Down, R1, Circle, Square, Left, L1 at the plane selection screen. 

More guided missiles
During the game play, press Right, Down, Left, Up, Triangle, Select,
R1, R2, X buttons on your controller. 

Laser gun
During the game play, press Left, Up, Right, Triangle, Select, Left,
Right, X buttons on your controller. 

Unlimited S skill
During the game play, press Right, Down, Left, Up, Triangle, Select,
Left, Right, X buttons on your controller.