Complete the game on Hard level to unlock a bonus helicopter and the maniac difficulty level. Complete the game on maniac difficulty level to unlock another bonus helicopter an which you can use on any difficulty setting.
set vibbration to 1 and sound effects and music to 0 then hold L1 + L2+ R1 + R2 + circle + square to see the "spooky cat" message. now you sholld be able to select any campein and play it.
