This is great cheat that will let you use any of the skills in the game regardless of their level requirement without having to learn them. To enable this cheat you have to edit the 'game.cfg' file adding the line 'AllCombos = 1' to it.
In your installation folder open the 'game.cfg' file and using Notepad change the line that says 'Debug = 0' to 'Debug = 1'.
Then add the line 'AllowConsole=1' to the 'game.cfg' file to enable the cheat console. When you have done this you can then press the following keys during gameplay to enable their corresponding effect.
If you're struggling with the game then try some of these cheats. To input them press the ';' key during gameplay to bring up the cheat console and then type in the cheat effect you want to enable in the game.