eZ Publish would certainly suit that type of deployment. With the content class model you can define the structure of your objects. You can relate articles, cheats, reviews to a particular object within the system.
I believe with GPL licensing you aren't forced to redistribute your changes, but should you distribute your changes, then when you do so it is with the knowledge that those people can also redistribute it to whomever they wish.
If the GPL license doesn't fit your legal requirements you can opt for a perpetual proprietary license which is available with any support and maintenance subscription from eZ Systems.
I have no problem with the GPL license, I asked because, for security reasons, we prefer to not redistribute or make public some parts of our code. Of course, if I have parts that have no problem sharing with others, I will promptly post them in the forums.
The licensing options are interesting! If we start making some little money we might go for one of them and resell some parts of the code we develop for our own website.