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:
NumPad1: Untouchable (MM 5)
NumPad2: Infinite Health (MM 5)
NumPad3: Unlimited Lives (MM 5)
NumPad4: Untouchable (MM 6)
NumPad5: Infinite Health (MM 6)
NumPad6: Unlimited Lives (MM 6)
NumPad7: Untouchable (MM 7)
NumPad8: Infinite Health (MM 7)
NumPad9: Unlimited Lives (MM 7)
NumPad0: Untouchable (MM 8)
NumPad/: Infinite Health (MM 8)
NumPad*: Unlimited AT (MM 8)
NumPad-: Change Score By (MM 8) 500

Editor Options:
Misc: Score (MM 8)

Notes:

Untouchable: While active objects such as projectiles won't hit you. This also makes you invincible.