As I don't know what Gex is personally - I would love a topic introducing what game it is and etc. I can see that as a pin in the "Information Channel" area. I like the other forum area titles and such. The only one that slightly confused me at first was "The Home Shopping Channel" but I read the description and understand what is meant to be there... I would think a name such as "The Call Center" or something would maybe be more suitable.
Appearance Wise: I like the different font you use, and it is legible to me. It's a fun font too. As for the theme, I think it obviously fits your subject. I love the green and black header. Post profiles and etc look fine as well! I don't have much else to add other than if possible maybe add a light version of your theme for those who prefer light themes... Unless I missed where that is accessible!
If I knew more about the game I may have more ideas on ways to create some more activity. I think you are on the right track though!