World War Z is a conflicted game. On the one hand, its developer has tried to revamp the first-person shooter genre by creating a new control system tailor-made for touchscreen devices. But, while the controls may be progressive, the gameplay all too frequently lapses into uninspired - and frankly quite tedious - shoot and collect missions.

It's not all bad news, though. In fact, World War Z's drab, grey surface betrays stabs or real colour and excitement. The game is probably at is strongest during its set pieces. Early on, you'll find yourself watching a tidal wave of zombies bear down on you as you stare helplessly from the back of a van. Later, you hop into a helicopter and must use a mounted canon to decimate the ever growing towers of undead which threaten to enshroud a building and overrun the survivors. These moments inject some real drama into the proceedings.

Rather than opt for a dual stick control system as default, World War Z offers a streamlined system suitable for one-handed play. To move, you simply tap the ground to create a waypoint. Dragging your finger across the screen will direct your character's eyeline, while hovering your targeting reticle over a zombie will prompt him to automatically fire. Bar the occasional tussle with the world geometry, this system works pretty well. Combine these control with the instance-style zombie encounters, and you have a game which often feels as much gallery shooter as FPS.

However, it's World War Z's bog-standard corridor sections where the game falls flat. Throughout these sections, you're encouraged to pick up files and tap into computers for experience. This is time-consuming and ultimately feels rather aimless, as the game doesn't tell you what you've found, or provide any motivation beyond the experience points.

Worst of all, when lone zombies appear, the game lapses into a melee combat mode. Gluey, unresponsive controls and a block system that's next to useless render these potentially exciting tussles nothing but joyless roadblocks. They also leave you cursing your character for not pulling his pistol in the first place.

World War Z does have its moments, and, apart from the melee segments, is a perfectly functional FPS. It's just a shame that these moments of excitement are the punctuation at the end of what is all too often a relatively dull sentence.