If you're old enough to have been around for the coolest parts of the 20th century, you know Duck Hunt. I don't need to explain this, do I? No. You know all about the bright orange gun and that annoying little dog and getting frustrated and walking right up to the screen and shooting an 8-bit duck point blank in the pixel. This is your childhood. And now, it's on your phone in a fantastic clone that utilizes the gyroscope in the best possible way.
Ignoring for just a moment the silly AR mode (which actually didn't work very well when I tried it), Duck Retro Hunt has one advantage over the myriad of Duck Hunt clones on the Play Store: instead of using a touch screen, you have to aim your phone in a gyroscope-powered virtual world to shoot the little birds.