Take the fight to the undead in Plants vs Zombies Adventures on Facebook

After two months of closed beta testing, PopCap has launched Plants vs Zombies Adventures on Facebook.

It's based on the Gold Award-winning iOS game Plants vs Zombies, a lane-based tower defence game in which garden plants fend off hordes of the undead.

In this new Facebook edition of Plants vs Zombies, you'll uproot those plants and take them out on the road.

In Plants vs Zombies Adventures, you see, the perennial protectors will travel between 12 different worldwide environments to defend against the undead.

With these new locations come some new combatants, namely ten new zombies and 11 new plants (available from day one). PopCap has promised to introduce more plants and zombies every month.

You will have to earn (or buy) access to this new content, mind. XP gives you access to new tiers, while Zombucks (from road trips) and Coins (from your town) go towards the new items.

Plants vs Zombies Adventures is, of course, a Facebook game, so you can expect some social ties. So, you'll find leaderboards to compare your piles of cadavers in this new game, and have the ability to send your own zombies to invade friends (or enemies).

The most interesting change to the Plants vs Zombies Adventures formula is the new multi-directional gameplay.

Much of the original Plants vs Zombies success was down to the accessible single-direction structure, with the shambling hordes dutifully shuffling down their track towards their goal.

With attacks now possible from any direction, though, the game may prove too overwhelming for casual players, even with the social hooks.

Plants vs Zombies Adventures is available now on Facebook. It should whet our appetites nicely for Plants vs Zombies 2, which will be released later this summer.