Can I detect when a game object fills the entire screen?

I am working on a game where balloons are falling in from the top of the screen. They bounce of the screen edges and each other. The player has to pop those balloons before the screen is fully covered by them. How could I detect this occurrence as to end the game? Thank you.

you could use a Trigger as large as the screen. the first balloon that cant enter it on its own would be the one not fitting in any more.

Hi @JamieCUnity
I think if you do like this may be you can detect the screen is full of balloons.

public int totalBalloones =0; //number of balloons on the screen
public int maxLimit;//maximum limit of balloons on the screen

OnBallonPop ()
{
totalBalloones -=1;
} //this fuction will be called when player pop the balloon

OnBalloonProduced ()
{
totalBalloones +=1;
} //this fuction will be called when new balloon was genrated

void Update
{
if(totalBallones >= maxLimit)
{
//screen is full of balloons
//Game over
}
}

May be it could help.