Deadly Skies

Play VS mode in Boss Stage

At the VS Mode Selection Screen, press L2, L1, Square, Up

Play VS Mode in 2nd Boss Stage

At the VS Mode Selection Screen, press L2, L1, Square, Down.

Level Select

At the title screen, press L2, L1, Triangle, Up

Infinite S.Skill

Right, Down, Left, Up, Triangle, Select, Left, Right, X

Increase Homing Missiles

Right, Down, Left, Up, Triangle, Select, R1, R2, X