IMO, the game decides these complex options too high for the graphics card. Thus resulting in low FPS despite altering the in-game video options. So, to turn the complex options off, you have to find and edit the graphics configuration file. This is found in the B&W2 program files. For example:
Program Files>Lionhead Studios>B&W2>Data
In the data folder, you should see a config file called 'Graphics'. Open this up in Notepad. At the top of the text file, you should see 3 main options, with the meanings of 1,2 and 3 next to them. Find your graphics card in the list, then alter the 3 numbers next to it. With the important one to change being the shaders number. Once you have turned the shader number down, the complex options should be removed and give you good FPS. The Res and Detail options could potentially be turned up, depending on your card. This is much simpler to understand when you view the config file for yourself.
