Red Shark Cheats

Use Notepad to edit GameSettings.script file in InstallDir\ folder of the game folder:

set bool ConsoleEnabled = true;

Set this, and then, then in the game you'll be able to bring up the console and enter following cheats:

SetImmortalMode - God Mode
LoadFullAmmo - Full Ammo
SetUnlimitedAmmo - Unlimited Ammo

Alternative codes
Type them in the console if the above ones don't work:

fullammo - Full Ammo
immortal = true - Immortality
god_mode = true - God Mode
unlimited_ammo = true - Unlimited Ammo
enabled_missions = true - Unlock All Missions

You can also change everything by editing Helicopter.script file in InstallDir\Common\ folder of the game folder.