how to make every game more visible in App Store? Some of my game really get high on the first appearance, how to keep its performance
Actually there is a set of steps that will bring you certain results. We'll try to list ones that we believe are effective enough.
1) Guess you've done this already... if not - reach out to the reviewers. The more coverage you get, the better.
2) Use forums like this to tell about your game, its progress (e.g. X downloads, got featured, etc.), news, updates.
3) Make updates regularly and distribute the news about it (via press releases, bloggers, social networks, forums).
4) Utilize FB and Twitter, interact with your followers. Post regularly, communicate with them, make small contests, etc...
5) Try to integrate your app with social networks (if you haven't done this already) to allow users share their results with others.
6) If you have a paid game, going free for a limited period can be good also. At least it will help to make a game more visible on the App Store (as well as other resources that track apps going free).
7) Apply analytical tools (such as Flurry SDK, AppAnie, Mobileapptracking, etc.) and keep track of your stats. This will allow you to see which measure was effective and which wasn't.