Hi!
I have the “feeling” that the app icon is crucial for a successful game.
Testing it once it’s been released for two months is very easy: you change the icon and then look if it goes up or down (I’ve got 200% increases in downloads changing them. And lots of decreases 
) Doing that while rising is very hard, because you never know when you’re just being helped by the “top new” ranking or it’s the icon.
Bad part is once you have been 2 months on the market your chances to convert an ill-fated game into a succesful one is almost 0.
Do you know of any way to test your icons before releasing, or in the first weeks of release?
thanks!
Kak