Let's not overthink this one. Gyro's a deceptively simple game in which you rotate a three-color circle, match colors and earn points. It's simple. It requires very little thinking. And it's an easy way to kill a few minutes. The game does get a little tougher as more and more balls come flying at you. But you've also got power-ups like shields and energy refills to help you on your way. Hit up the free download below.