Thunder Strike: Operation Phoenix Cheats

Successfully complete the game on the hard difficulty setting to unlock a bonus helicopter and the "Maniac" difficulty setting. The bonus chopper flies faster, turns faster, ascends/descends faster, the front-mounted cannon fires faster and takes longer to overheat and cools faster, and the rotor sounds a little different. Successfully complete the game on the "Maniac" difficulty setting to unlock another bonus helicopter, which you can use on any difficulty setting. It has the same top speed and fire rate as the other bonus helicopter, but more armor.
Game Shark Codes
Master Code (Must Be On) EC878280 1449D2E4
Infinite Armor 4CC1D49A 1456248F
Infinite Ammo Weapon 1 4CD5B248 1456E788
Infinite Ammo Weapon 2 4CD5B24C 1456E788
Infinite Ammo Weapon 3 4CD5B250 1456E788
Never Overheat 4CC1D48C 1456E7A5

Go to the Options screen and set 'vibration' to 1 and 'sound effects' and 'music' to O.
Hold down L1+L2+R1+R2+CIRCLE+SQUARE until the message 'spooky cat' appears.

Complete the game on Hard difficulty to unlock Maniac difficulty and a bonus helicopter. Maniac difficulty is the most difficult level of all difficulties in the game. With the new bonus helicopter, your helicopter's speed, dive, and climb abilities is much faster than the normal helicopter you had from the previous game.

Go to the options screen and set Vibration to 1, Sound Effects to 0, Music to 0. Now hold L2 + L1 + R2 + R1 + CIRCLE + SQUARE. If you did it correctly, you should see blinking letters saying "SPOOKY CAT".