I'm having an issue where the World of Warfare add (the huge background add) is eating into at least 2 of the games I play, since it layers on top of the games. The games I know for sure are Clicker Hero and Time Clicker.
Also, I find it annoying to painful that the ad doesn't open a new page/tab when clicked on. In the past I've lost a lot of time and effort in games like Gemcraft Labrynth, due to clicking links accidentally, and having the page automatically redirected.