OK, hands up if you thought that EA would be the big publisher to launch a free-to-play game that doesn't gouge the player? That Plants vs. Zombies 2 manages to use in-app purchases in a non-abusive way that doesn't nerf the game design is perhaps its most surprising feature, but there's more to it than good business practice. This is a long overdue sequel that evolves a winning formula in fun and challenging ways.
The gameplay seeds planted in the 2009 original remain largely unchanged. A parade of zombies advances from screen right along five rows, and you place plants of varying abilities to fend them off. Should a zombie make it all the way across - and past your lawnmower last line of defence - then it's game over.
Almost immediately, Plants vs. Zombies 2 starts to tweak and embellish that core concept. The story this time around is that Crazy Dave, the pan-wearing vendor from the first game, wants to travel back in time to eat a particularly delicious taco again. Unfortunately, his time-travelling RV ends up sending everyone back to Ancient Egypt. Now you have to make your way through a series of challenges to get back to the present and taste that delicious Mexican treat.
Progress this time is along a linear pathway of the sort familiar from most casual games. Each level passed opens up the next, but there are none of the expected freemium tricks to delay your journey. There are no cooldown timers here, and the game never makes you wait four hours for something to grow. Nor are there any depleting energy reserves to break the game up into paywall-infested chunks. That allowing you to keep playing without crude interruption feels refreshing and generous says a lot about the sad state of free-to-play gaming on mobiles.
What developer PopCap does do is divide the experience between a fairly simple main game, which can be completed without much trouble by even the most casual player, and a deeper, more tactical game designed for those who really want to see everything Plants vs. Zombies 2 has to offer.
It makes all the difference that it's player skill rather than Facebook shares or mindless patience that ultimately opens the way
Upon reaching the end of the game's three themed time zones - Egypt, Pirates and Wild West - you're faced with a Star Gate that requires a certain number of gameplay stars to pass. To help you reach the required number, all the previously played levels are refreshed with three new star challenges that force you to play differently - faster, smarter, more efficiently. For those who can't be bothered earning the stars needed, you can pay to bypass the Star Gates for £2.99 a go. It makes all the difference that it's player skill, as enabled by new gameplay, rather than Facebook shares or mindless patience that can ultimately open the way.
There are other deviations from the norm as well. Forks in the path can only be unlocked with keys. These aren't handed out often, but it's worth saving them up, as some of the game's best plants and abilities are found behind these gated diversions. Similarly, the end of each world unlocks a special endless mode location where you get to add one new plant to your line-up with each round as you see how long you can last.
Even in the levels themselves, PopCap keeps playing around with its own formula. This is a much more frantic game than the original, frequently giving you the chance to get involved in the action directly. It does this most obviously through a trio of power-ups, available at any time using your in-game coins. These allow you to pinch the heads of zombies yourself, flick them off-screen or zap them with electricity. All are good for clearing the screen in an emergency, but all cost enough coins that you won't use them lightly.
Alternatively, you can use plant food, which is dropped by sickly green zombies (well, sicklier and greener than the usual). Use plant food on any plant and it's immediately supercharged. Peashooters deliver a machine gun spray, for example, while sunflowers belch out a bonus shower of precious sunshine.
Both mechanics could easily have been a magnet for craven monetisation, and you can purchase more with real money if you want, yet the game dishes out enough coins and plant food through normal gameplay for them to be freely available at all times. At every turn, the in-app purchases of Plants vs. Zombies 2 feel like they're there to assist unskilled or lazy players, rather than to punish those who play with skill.
Crucially, these additions don't sit on top of the existing Plants vs. Zombies gameplay but become a natural and essential part of it. Managing your plant food reserves, choosing the right plant and the right time to use it, knowing when to intervene with your own finger-powered acts of God: these are all important strategic choices, made in the moment, and they don't break the fiction with a checkout icon.
Where Plants vs. Zombies 2 does erect a stark, all-or-nothing paywall is around access to a handful of plant types from the original game. If you want the fiery Jalapeno or the pounding action of a Squash, you'll need to buy them separately - and at a few quid a pop, they're not cheap. But then, nor are they essential. I found I missed them more for sentimental reasons - the Torchwood formed a central part of my go-to strategies in the first game - but rarely did I feel like I needed them.
That's because there are some fantastic new additions, sitting alongside troopers like the Peashooter and Cabbagepult. As its name suggests, the Bloomerang tosses out a boomerang that can hit multiple targets on the way out and the way back. Coconut Cannons deliver powerful payloads and can be manually fired with a tap. One of the most useful is actually the small and humble Iceberg Lettuce, which freezes any zombie that steps on it, but when powered up with plant food will freeze every enemy on the screen. It's here that the game's new additions really come into their own, as you discover the game-changing properties they offer when supercharged.
The zombies, too, have changed to suit, with each time zone offering distinctive new enemy types that require fresh tactics. Egyptian zombies advance hiding behind stone slabs, whirling in sandstorms or encased in their sarcophagus. Pirate levels feature zombies that swing across the screen, carried by seagulls or shot out of cannons. Pirate captains will send their undead parrots to steal one of your plants. In the Wild West, you can place plants on rail cars that can be moved up and down the screen, allowing one plant to cover multiple rows.
In keeping with its horticultural theme, Plants vs. Zombies 2 has deep roots and many branches, and it bears fruit in a game that feels at once familiar and refreshing. There's always something new coming up, be it a never-before-seen plant type or a level that shakes up the rules or controls in fun ways. Soon enough, the fact that this is a freemium title fades into the background and you're left to contemplate the game itself: witty, inventive and addictive. The sequel we were hoping for, in other words.