It's a funny game. but it will be better on a dark background. bcoz the icon will contains a dark gray border either. Moving the frame may cause it easy to be seen.
The website works for iphone only
Using a transparent png won't work neigther, demo shows that XCode may "recognize" it and show as an black icon, it will also ignore the "Icon already includes gloss effects" and add gloss automatically.
http://www.addictivetips.com/ios/add-transparent-icons-to-ios-home-screen-without-jailbreak/