This is a Zen type game. You use rockets to destroy drones. You can never get better than 100% so once you fire and hit 1 drone you are at 100%. The best you can ever do is 100% so don't worry about it. You never need to fire the rocket and can just watch the drones fly by. If you want to be clever you can set the speed to be very slow and then launch your rocket and when you spot your prey speed up, or slow down, the rocket while it is in flight.

Rocket - Fire rockets to destroy drones.

Rocket is a Zen game to shoot drones with a rocket. You can select, even in mid-rocket-flight, your speed, with the right-side top and bottom buttons. You fire your rockets with the middle button. The % of hits is based on the number hits over the number of rocket launches. The Zen of this is that the % of hits is only counted when you fire the rocket. You can let the drones go by for hours with no change to your score.