Unity: Instantiate and Destroy

What I created

I have created a simple design that includes scripts that effect the way the level works. At the start, the ball falls down each platform using a timed script where the platforms disappear.  The yellow triangle will kill the player and restart the level so there is some sort of danger in the level.  When the player is on the red platform, the first ball will get stuck and the player will have to click to spawn another ball onto which will let them go onto the next section.  The blue walls will disappear on collision to unlock the next area.  The orange corner peace bounces the player up.