The secret is to tap the keys rather than press. Don't jerk from one side to the other but wait until the next lot of ducks appear. You may also find that the next lot come up where you've just hit so wait a sec. Work your way along the line. Someone told me to mark on your screen what level you should be aiming for as that is the main problem at the start. Unfortunately you have to hit every one, as if you didn't know! I found it helped turning the sound off as it just made my heart pound even more. Enjoy.