Woah I actually looked into this but only looked at ign and metacritic who don't have apis. Thanks for pointing out these two apis. would be itnerested in an addon such as this as well for reviews and game info.
I'm not exactly sure what I'm doing right now. I want to get the review system off the ground. If it doesn't, I'll probably just keep working on my small add ons and possibly the game database thing.
I looked at these apis the day you posted this and I noticed that on one of them (forget which one off the top of my head), they don't want you to resell any of their content. I'm not sure if that is included in what I'd be doing so I have to contact them if I do start development of this.