As their site (www.stopzombiemouth.com) says, "[they're] giving away Plants vs. Zombies download games as a sugar-free alternative, and you can join in the fun."
Grab yourself a free coupon (attached) and while you're at it, stash up a bunch in your reception area of your home so that when you get beset upon by miniaturised zombie-wannabes you can give them the gift of gaming instead of the prognosis of halitosis.