Activating this trainer:
Press F1 at main menu.
Listen for 'Trainer Activated'.
Press desired hotkey. All hotkeys can be changed on the trainer.

Promo Options:
NumPad5: Slow Motion

Trainer Options:
NumPad1: Change EXP By 500
NumPad2: Change Level By 1
NumPad3: Change TP By 50000
NumPad4: Super Speed
NumPad5: Slow Motion

Editor Options:
Misc: Level
Misc: EXP
Misc: TP

Notes:

Level / EXP / TP: At main menu go to shop, click on a category and visit a page where the item cost is shown. Now press hotkey or use editor. All changes won't immediately show up ingame instead only when the value changes by the game. So for TP for example buy an item after you added more money to see it has changed.