Activating this trainer:
Press F1 at main menu.
Listen for 'Trainer Activated'.
Press desired hotkey. All hotkeys can be changed on the trainer.
NumPad1: Infinite Health
NumPad2: No Reload / Unlimited Ammo
NumPad3: Unlimited Item Spawn Duration
NumPad4: Infinite Ability Time
NumPad5: Change EXP By 5000
NumPad6: Change Money By 5000
Unlimited Item Spawn Duration: While active items spawned by enemies don't disappear over time.
Infinite Ability Time: When you collect a perk/item which gives you something over time. The time will not decrease while this cheat is active.
Unlock more trainer options including updates from here - Versus Game Trainer