Activating this trainer:

Press F1 at main menu.

Listen for 'Trainer Activated'.

Press desired hotkey. All hotkeys can be changed on the trainer.

Trainer Options:

Numpad 1: No Damage To Player Soldier

Numpad 2: Unlimited Ammo

Numpad 3: No Reload / Unlimited Grenades

Numpad 4: Player Soldier is Invisible

Numpad 5: No Weapon Overheat

Numpad 6: Improved Weapon Accuracy

Numpad 7: No Weapon Recoil

Numpad 8: Super Damage

Notes:

Trainer is for SINGLE PLAYER, WAR STORIES part of the game.  Using this online against other players is likely to get you banned!

Numpad 1: No Damage To Player Soldier - toggle on and most things cannot harm the infantry soldier you are controlling.

Numpad 2: Unlimited Ammo - toggle on and most weapons have unlimited ammo.

Numpad 3: No Reload / Unlimited Grenades - toggle on and most weapons you can fire them without reloading.  Also may give you unlimited types of grenades and certain other items.

Numpad 4: Player Soldier is Invisible - toggle on and the enemy soldiers do not react to your soldier.  It's best to leave this off until needed for stealth missions, and even then only when needed to get by the units without detection.  Leave off until needed.

Numpad 5: No Weapon Overheat - toggle on and some weapons that generate heat when fired will no longer do so.

Numpad 6: Improved Weapon Accuracy - toggle on and most weapons, the crosshairs and accuracy of the weapon are improved.

Numpad 7: No Weapon Recoil - toggle on and most weapons will not kick or move about when fired.

Numpad 8: Super Damage - toggle on and the damage to soldiers (including you!) is massive.  It's probably best to toggle on Invisible option, then use this option only when necessary to kill a large number of AI quickly.  Leave off to avoid unnecessary accidental deaths of the player.