Using this Trainer:

Launch the trainer first, then launch the Game and then Press F1 at the Main Menu.

Listen for "Activated".

Press desired option key

Options in Promo:

Numpad 3: Unlimited Ammo

Options:

Numpad 1: Reduced Damage

Numpad 2: Unlimited Jumps

Numpad 3: Unlimited Ammo

Numpad 4: Reduced Ship Damage

Numpad 5: Unlimited Ship Ammo

Notes:

Numpad 1: Reduced Damage - toggle this on and most types of damages are mitigated.  Keep in mind, however that some events or damage types have nothing to do with health and are 'instant death' scripted trigger events.  So while this will keep your health at 100% for most attacks, scripted deaths cannot be prevented.

Numpad 2: Unlimited Jumps - while this is on you can keep pressing the jump button once in the air and continue to go higher or to stay in the air.  You may need to jump twice before using before the trainer can toggle the option on.

Numpad 3: Unlimited Ammo - while this is on, you can shoot most weapons without the ammo depleting.  You may need to fire a weapon at least once for the trainer can toggle the option on.

Numpad 4: Reduced Ship Damage - during the part of the game you are flying the ship, toggle this on to help with most damage.

Numpad 5: Unlimited Ship Ammo - during the part of the game you are flying the ship, toggle this on for unlimited ammo.