There's really not much more to it than telling you that you just have to concentrate / focus really hard to get thru all the rounds with the right flags. Sometimes I lose because I get distracted by a noise or someone talking in the background (or talking direct to me whilst I am playing) and then I accidentally press the wrong button.
Have you read thru' this topic on how to play the V4 games? https://www.tamatalk.com/IB/index.php?showtopic=103000 - the hardest ones to beat are the trick flags that appear on the opposite side (like the black flag appearing on the white flags side of the screen).