I ran out of ammo and ran off to find some more, all panicked like. I noticed as I ran that no new zombies seemed to be arriving on screen. I shot one of the huge horde that was following me and – lo! – a new one appeared.

I tested it some more, running around for ages, leading the slow shambling mass of rotting flesh around the level. No new zombies. Shot a couple in the horde, two more appeared from offscreen.

So it appears that there’s a maximum number of zombies that the game can put in a level and, if you manage to get a load of slow ones, you can simply lead them round the level to your heart’s content.

It doesn’t affect the leaderboards or leveling up your character, as they both appear to be tied to the points that come from killing, but it does allow you to run around for ten minutes to unlock the super gold pistol.

It feels a bit cheap, but it’s an awesome gun. I went back into Survival mode after unlocking it and lasted nearly five minutes using that gun alone. That’s really not bad for a sub weapon. And, yes, I was actually killing zombies that time.

After I few tries I even managed to beat the boss in less than a minute to complete the challenge for that level.

The new gun hasn’t helped so much in Survival mode, though. My new best is about five and a half minutes, so it’s only given me another minute or so.

Maybe I need to get better at the game instead of relying on stat upgrades? That’s a shocking thought.

I’m enjoying this game so much more after the update to version 1.1.

On Saturday morning, though, the game updated to version 1.1, which adds some excellent new stuff.

First off there’s a survival mode, where the aim is simply to go as long as possible without dying. You get a special gun if you last ten minutes – I’ve managed about four and a half so far.

Then there’s Horde mode, where you have to survive waves of zombies, with guns being given out for surviving a certain number of waves.

They’re both good additions, making leveling up a lot more interesting than simply going back and playing early levels.

The best new feature, though, is a lot more simple – there’s now an icon next to a level that appears when you’ve completed that level’s bonus challenge. No longer do I have to try and remember which levels I’ve completed fully, hooray!

So I played a lot of this at the weekend. The first seven levels are pretty simple, but there’s a big jump in difficulty at level eight. I managed it after a few tries, but I’m now having quite a lot of trouble on level nine. Great fun, though, and the update has made the game a lot more enjoyable.

Well, pretty much every zombie game except Resident Evil.

But this game does has zombie dogs.

You have to shoot them.

Um, I don’t have much to say about this that I’ve not already said.

I still think it’s very good.

It looks like this.

So, yes, it’s another top-down, twin-stick shooter. It’s a good one, though. The controls work nicely and each level has a main objective and a bonus objective. The first level tasks you with killing sixty zombies, the challenge is to kill them in less than three minutes. A few levels later and you have to rescue a survivor, the challenge being not to let any survivors die. The level after that asks you retrieve a briefcase with a vaccine in it, the challenge wants you to kill fifty zombies on the way. It mixes things up nicely, especially as survivors need to be protected as shuffle slowly to the safe zone and when carrying a briefcase you can only use your pistol, rather than your main gun.

There’s even an RPG-style levelling system, that lets you upgrade your character.

You also earn money for new weapons by completely levels and doing challenges gets you bonus equipment, like extra health or ammo. It’s a nice system that keeps you play and it all adds up to being one of the best shooters on the App Store, even in single-player. (I doubt I’ll ever be able to try the multiplayer mode.)

My only quibble right now – apart from the standard problem of your thumbs obscuring the bottom corners of the screen – is that you don’t seem to be able to see whether or not you’ve completed the challenge for a level when you’re selecting a level to play. That’s going to be annoying, I think.