Activating this trainer

If not state otherwise below, press F1 at main menu.
Listen for 'Trainer Activated'.
Press desired hotkey. All hotkeys can be changed on the trainer.

Trainer Options

# Player 
     NumPad1: Unlimited Health
     NumPad2: Unlimited Stamina
     NumPad3: Unlimited Ammo
     NumPad4: Fly
     NumPad5: No Clip
     NumPad6: Hover Player Higher
     NumPad7: Hover Player Lower
     NumPad8: Change Player Speed
     NumPad9: Increase Player Speed
     Multiply: Decrease Player Speed
     Add: Set Normal Player Speed
     Separator: Change Player Jump Height
     Subtract: Increase Jump Height
     Decimal: Decrease Jump Height
     Divide: Set Normal Jump Height
     F1: Change Player Gravity
     F2: Decrease Gravity
     F3: Increase Gravity
     F4: Set Normal Gravity
     F5: Change Enemy Speed
     F6: Decrease NPC Speed
     F7: Increase NPC Speed
     F8: Freeze NPC
     F9: Set Normal NPC Speed

# Teleport 
     F10: Save Position Slot 1
     F11: Save Position Slot 2
     F12: Save Position Slot 3
     F13: Save Position Slot 4
     F14: Save Position Slot 5
     F15: Restore Position Slot 1
     F16: Restore Position Slot 2
     F17: Restore Position Slot 3
     F18: Restore Position Slot 4
     F19: Restore Position Slot 5

# Game  
     F20: Game Speed

Notes

No Clip:
It doesn't works without Fly.