I have an iPhone 5S. It's not so great for gaming since it's storage is rather small(I have a 16GB), and the screen is good, but not great. Even the games with better graphics can come off as a little bit clunky and sharp. The battery life of an iPhone isn't too reliable, so its best to invest in a portable charger. When playing games, the phone can get very hot very quickly, which is also a minus. The screen's brightness and the adjust of the brightness is great, though.