PopCap has finally lifted the lid on the forthcoming sequel to its hugely successful vegetable and corpse mash-up tower defence game, Plants vs Zombies 2. It has also released a trailer, giving a glimpse of what to expect when it hits iPad, iPhone and iPod touch on 18 July.

The gameplay has been enhanced, but is similar to the original - with the player having to lay plants with different powers on a map to stop ever-advancing, brain-eating zombies. However, the sequel has been built from the ground up "as a live service", although no further details on what that entails have been released yet.

PopCap has revealed some of the key new features, however, including new worlds with new levels, plants and zombies. Plus, there are new touchscreen power-ups which "break the fourth wall", allowing the player to interact with the zombies directly.

One of the biggest changes with Plants vs Zombies 2 is that it will adopt a freemium model. The game will be a free download on iTunes with additional items and upgrades available through in-app purchases. The developer does emphasise though that every level will be playable without payment, as will the ability to face every zombie.

"It's about time," said Allen Murray, senior producer for Plants vs Zombies 2. "We're confident that players will see the love and attention we've put into this game. We've created wild new ways to experience the plants and zombies you know and love as well as packing the game with tons of completely new content, and we're still hard at work coming up with even more cool stuff that will keep Plants vs Zombies 2 fresh and evolving in the months and years following launch."