Doublesix, it would seem, cares deeply about its players' enjoyment, but it doesn't trust them to have fun free from its guiding hand. Twin-stick shooter All Zombies Must Die! piles on new mechanics, ideas and systems at such a bewildering rate that at times it's hard to keep track.
Zombies come in various decomposing flavours including vanilla, electrified, irradiated and, our personal favourite, ablaze, while objects in the environment can modify them – an abandoned police car's siren turns the nearby crowd of undead into stronger 'sonic' zombies, for instance, while toxic goo creates mutants. A weapon crafting system allows you to combine special ingredients – indigenous to the various maps and obtained by fulfilling certain conditions within them – with your arsenal to create colourfully-named hybrids such as the Napalm Lick Chainsaw or Rumble Cleaver Cricket Bat. Did we mention the stacking combo system, character-switching side-quests and hidden collectables?
All these elements are combined to great effect: Running low on ammo? Lead a zombie past a burning stack of tires and watch as it sets light to any others that give chase while you pick off the weakest ones with your cricket bat. Doublesix has created a superbly open and chaotic ecosystem; an emergent playground.
Or at least it would have were it not for the gates. These barriers require you to complete a task – kill 15 jogger zombies, say, or find a set number of items from around the area – before opening. Initially engaging challenges, they begin to grate when you realise that a new task will be set for you every time you attempt to move between areas, and by segmenting the action they curtail its gloriously freeform nature. Any zombies dispatched en route to the gate don't count, and to top it all off, if you die, your progress in that area is wiped. This makes travelling across the game's city map stilted at best, but nothing less than tiresome on longer treks. One particularly ill-fated journey was cut short when, having battled our way through three areas, the final gate revealed we needed a different character to gain entry.
Some of these problems are mitigated by playing with friends, four-player co-op enabling all characters to be present and taking the sting out of individual deaths, but in time the constant grind will still take its toll. Like any good zombie fiction, the real enemy in AZMD! isn't the walking dead, but the humans who created them.
Xbox 360 version tested.