Hold down space to pull bow back and release to fire. The longer you hold down the more accurate the shot will be, but if hold down to long, the shot will go high. The closer to the center you go, the less points you will get. A perfect score is 0. Try to get as little points as possible is 60 seconds. -oh yeah... don't try to cheat by not shooting. You might want to shoot at least 1 shot every 15 seconds :D
To get the score, I used the 'Distance to' block in a 'round' block. For the moment I've made it you get as little points as possible, but that may change. Try to beat 18. That's my best.
