If you didn't get early access to Plants vs. Zombies 2 on iOS, now's your chance to play -- PopCap's backyard defense game has just launched worldwide on the App Store. The time travel-themed sequel significantly expands on the original with new plants, new zombies, between-round maps and touch-controlled power-ups. We've tried the game, and it's a welcome refinement of a mostly familiar experience. For some, though, the big change in PvZ2 may be its sheer accessibility. This is a genuinely free-to-play title -- you can see virtually everything it has to offer without paying a dime. In-app purchases are largely restricted to perks, such as coin packs. The developer doesn't yet have a schedule for PvZ2 releases on other platforms, but those who have at least one iOS device can engage in herbal warfare at the source link.