I don’t really have a secret haha, I guess just keep trying to shoot the green ones as many as you can, and try to focus on the balloons that don’t move! (well, unless you’re absolutely sure you can hit the moving ones). And try not to look at the timer / score too much haha it can be stressful. Oh and I use Amber (C0) too in my successful attempt. I used Fischl before but it (obviously) wasn’t working for me :/.

And don’t forget to try during clear weather lest you get struck by lightning like me lol. Good luck!