In level 1-5 you are tasked to bowl with Wall Nuts, to take out zombies. I see that the wall nuts bounce, but they seem to bounce randomly. It seems like it is important to get multiple hits with each Wall Nut, but I can't figure out how to make it bounce up vs. down. Can it be controlled?
From my own experience, you can't control which way it bounces.
From plantsvszombies wiki:
It says nothing about which direction it bounds, up or down, so my guess is that it's somehow random.