Thanks for your kind words.
Strictly speaking, this forum is for assistance with the "Matty Theme QuickSwitch" plugin. That being said, I'll try and point you in the right direction towards resolving your query. :)
Upon inspection of your website, it looks like you've got a few pages that use a custom plugin or custom code to display a grid of newly-released PS3 games.
If you're noting an issue with posts not displaying in a post category, I'd advise making a full backup of your website and, once done, deactivating plugins until you can isolate if a plugin is conflicting with the query used to display posts within a category.
If you don't feel comfortable deactivating plugins and didn't develop the website yourself, I'd advise contacting the developer of the website for further debugging and assistance in this regard.
I hope this helps, Brett. All the best with resolving your query. :)