NOTE: These are the main Far Cry cheats that are usually applied by pressing down the right key combination. Please find the instructions on how to use these cheats below.

Press [~] to access the console, then enter one of the following codes to activate the corresponding cheat function:

god_mode_count=1 - God Mode
give_all_weapons=1 - All Weapons
give_all_ammo=1 - Ammunition
save_game <file name> - Quick save game
load_game <file name> - Load quick save
map <map name> - Load map (see the list below)
ca_Debug=1 - Debug mode
ai_noupdate=1 - Dumb enemies

Map names: archive, boat, bunker, carrier, catacombs, control, cooler, dam, factory, fort, pier, rebellion, regulator, research, river, steam, swamp, training, treehouse, volcano

Another method
First off, download the cheat enabler listed above and unpack the DevMode.lua file to the main FarCry directory overwritting other file (make a backup of it!).

Now you need to modify your desktop shortcut. Right click on the Far Cry icon on your desktop, select properties and a new screen should pop up. Add the " -DEVMODE" parameter (without the quotes) at the end of the target field so it looks similar to this:

"C:Program FilesUBISOFTCrytekFar CryBin32FarCry.exe" -DEVMODE

Click Apply to save the changes and run the game using that shortcut. All levels will be unlocked and you'll be able to use the following buttons:

[F1] - Toggles first/third-person camera modes
[F2] - Move to next checkpoint
[F3] - Spawn point
[F4] - Toggle no-clip mode
[F5] - Default speed
[F9] - Save current position
[F10] - Load current position
[F11] - Toggle extra information
[=] - Increase speed
[-] - Decrease speed
[BackSpace] - Toggle God mode (if it doesn't work for you use the God mode cheat from below)
o - Gives 999 ammo
p - Gives all weapons