ADA and PopCap Games are giving away free copies of Plants Vs Zombies game for PC / Mac this Halloween. As per the site stopzombiemouth.com :

“This Halloween, the ADA and PopCap Games are redefining what a Halloween “treat” can be… by giving FUN instead of candy. We’re giving away Plants vs. Zombiesâ„¢ download games as a sugar-free alternative, and you can join in the fun.

Ask if your local dentist has the limited-edition, collectible Plants vs. Zombies trading cards with the code for a free Plants vs. Zombies download game. Or, download printable free-game coupons here.

Now go out and give PvZ fun as a Halloween treat to kids of all ages. And thanks for helping Stop Zombie Mouth!”

Get the free coupon for the game here.