Zombie Ace ticks almost all the right boxes for releasing an instant hit: It's free, it has zombies, and it's packs single-touch controls for the ultimate in accessibility. Hothead Games have crafted their latest release to a fine point for piercing the market, but all of these buzzwords will fall apart if the gameplay doesn't hold up to scratch.

As with so many other zombie-related games, the undead, brain-chomping misanthropes are out to infect the populous, but instead of slowly shuffling their way along the ground, they've taken to the skies to speed things up a little. Your job as a pilot is to navigate the many hazards the block your path, from the military, to natural hazards and even a Sasquatch, in order to land and drop-off enough zombies to infect a town along your route.

This sounds simple enough, but your passengers are also your ammunition, with a tap on enemy vehicles flinging a single zombie willing to sacrifice themselves in order to save everyone else. Larger vehicles will require more zombies to blow them up before you perish, but often you'll be rewarded with a pack of coin carrying undead to replenish your passengers and boost your coffers at the same time.

Death is but a small obstacle for the tenacious undead and while coins and brains earned through play can be spent on upgrades and power-ups, you can also get lucky thanks to lottery tickets and the occasional helpful vehicle that passes by to extend your run.

However, if there's a downside to picking up Zombie Ace it's that it can feel all too aggressive when it comes to its advertising, sneaking in videos and pop-ups (albeit with compensation in the form of brains) that become either monotonous to listen to over and over or otherwise frustrating to have to skip should you mindlessly press the 'tick' buttons in the regularly appearing confirmation boxes.

Aside from this sour note, Zombie Ace is a delightful title that revels in its variety and those willing to take the time to infect the United States are duly rewarded with a fun time-waster.