I would suggest a better header for the top. Arcade sites are so common that you really need some kind of "branding" that will catch they eye and make your different from the get go. The domain name is great! So many possibilities for a logo!
That is about all I can think to change on this one. I wish you luck! :tu:
The skin looks awesome, sharp. But firstly, the header point is totally on spot. You need to make real flashy logo for your arcade, it looks pretty much static with the slogan misplaced as well.
I love the placement of your AdSense.
One thing you need as well is a favicon that is unique to you. People will remember you.
That's all I can think of for now, all in all awesome job, but I suggest working on a more classy logo.