Yeh, it is a very blurry subject that changes with every algorithm update!
Getting good permanent link from authority sites has to be the way to go. I have seen this work for some other businesses I run that are far less competitive than online gaming and you sure can dominate areas with not much competition with a slight bit of SEO knowledge.
There are some great SEO blogs and podcasts out there. One great one I found is the Delicious page for Wil Reynolds. I saw Wil at Affiliate Summit West in Vegas and he talked a lot of sense.
The link is http://del.icio.us/wilreynolds