One thing that never fails to amaze me about having so many developers trying their hand at breaking in to the iOS market is seeing the creativity that comes from adversity. One of the defining features of the platform is its touch screen, but it can be as much a curse as a boon. Twin-stick shooters have reached an almost amicable middle-ground of 'it works, but isn't perfect' situation, but developer ShortRound have broken out of the box with their latest work for publisher Chillingo with Extraction: Project Outbreak.

Instead of moving with one thumb and shooting with the other, the game has been reduced to a single-touch system of swipes and taps. Initially you'd think you'd be tapping enemies to fire and swiping around to move your player, but you'd be horribly wrong. Tapping sets a location to move towards, while swiping allows you to target and set the order in which your character fires upon them.

At first this may not seem drastic, but it allows for a lot of tactical depth as you select a zombie behind one closer to you to score a few free hits if your bullets go astray. If you can swipe and select zombies smoothly and at the right speed you'll also pull off 'trick shots', adding to your damage output. This said though, the game is far from challenging to complete as you're rarely faced with huge odds. Also, credits earned throughout each mission type (kill x of y, or escort) allow you to upgrade and unlock powerful weaponry to keep enemies at bay, making it easy to rip through the ten available zones (multiple missions available for each one).

The repetition and lack of challenge brings down what is an otherwise excellent shooter packed with amazingly detailed levels and a control system that, given the right amount of zombies or even new enemies, would result in incredibly intense battles.

Developer ShortRound has already hinted at including a hardcore mode, a new game mode, and boss battles in to the game, but even without these the game is certainly worth checking out if only to experience its unique control system.