This is the primary problem with Wikipedia, especially moving further into the age of Internet.

Not everything can be or really even NEEDS to be sourced. Need a source for the information? Launch the game! It's as simple as that, really.

Wikipedia runs into this with many of their articles that reference video games. I'm not sure how much more of a source is needed than the game itself.

And when it comes to controversy, many video game controversies are sparked in forums, which are often not very reliable over time as they are usually fan driven and those that aren't see threads get archived after a period of time.

It's a failure on Wikipedia's end that I don't see the organization correcting any time soon.