If it shows a steady record of revenue for at least 6 months, it may be worth the average of the revenue x (a minimum of ) 6 months or more to someone looking to own that type of site. I'm not into game sites, but it seems as if you have done a decent job on it.
Thank you! I can't talk about the last 6 months because the economy was so screwed, and if not screwed, my site wasn't even popular yet.