I finished a whole first adventure of Plants vs Zombies, but NO ZEN GARDEN. I have Quickplay, some awards, a key to Crazy Dave's shop, but no Zen Garden. Is it because you have to have a certain device to get the Garden? I'm confused. Do you unlock it in the second adventure? That I would understand. I even defeated the Zombot on the very last level! Do you need the Yeti Zombie to get it?