How to disable swipe down for Notification Center in apps on iOS?
https://discussions.apple.com/thread/3419084 has a person saying 


  For apps which are running in full-screen (includes games, but also built in apps such as YouTube and Photos when they are in full-screen mode), the gesture which normally brings down the full notification center just brings down a little gray tab at the top middle of the screen. You can then slide that tab down, if you really want the notification center.


iOS 7 Make Control Center hard to open like fullscreen mode while still showing status bar

shows an example of control centre pullup gesture where a small arrow appears which forces us to swipe twice to get control centre in full screen apps. An answer says that


  The system will only show this tab when the status bar is hidden.


So most likely it is upto the developer to make appropriate changes to use this feature, instead of covering the screen in one go.