Since you are using prebuilt script I am assuming you can't really make any changes to it unless you are good at coding and design Therefore, I think you should more focus on the promotion side of it. SEO/link-building and what not. Also consider purchasing a premium template.
It doesn't have much flare, but having a point system will be rather helpful, especially if you start building a community on the site. I think that it is a clean-looking site, but most of the games can be played on larger portals. If you had original or maybe exclusive games, it might draw more players. Also, having a sponsored game posted on other sites might draw more attention to your site.
That's fine. First of all need to say that you have a chosen a short and nice website URL for your games site. And it has enough information and lot's of games for game lovers. Congratulations!.