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: Unlimited Health

Numpad 2: Unlimited Stamina (No Stress)

Numpad 3: Unlimited Ammo

Numpad 4: No Reload

Numpad 5: 99 Lives

Numpad 6: 99 Mission Aleph

Notes:

Numpad 1: Unlimited Health - while in the combat portion of the game toggle this on for unlimited health.

Numpad 2: Unlimited Stamina (No Stress) - while in the combat portion of the game, toggle this on for unlimited stamina.

Numpad 3: Unlimited Ammo - toggle this on during the combat portion of the game and most weapons have unlimited ammo.

Numpad 4: No Reload - toggle this on during the combat portion of the game and most weapons that have more than 1 shot in the clip won't need reload.

Numpad 5: 99 Lives - best to use this right at the start of the mission when you can see your lives left.  Press and wait 5 seconds or so and you should have 99 lives.

Numpad 6: 99 Mission Aleph - toggle this on during the combat portion of the game and you have 99 Aleph.