On stage 2-2, I seriously don't see how to beat it. Anyone beat it? I tested it and between me doing nothing and me trying several different strategies, there was an 11 second difference from Mission Start to Mission Defeat. It was just a matter of time till yellow fell and then it was 6:1 odds. To be honest, the other levels where fairly easy. But in trying to make this one difficult you made it impossible. Ramp up the defenses of the yellow player, or we are all doooooomed!
It's supposed to be a secret!