Zombies, guns, first-person perspective. It's a formula that's hard to mess up and MADFINGER Games certainly doesn't drop the ball with DEAD TRIGGER, a rote, level-by-level approach to shooting the undead with increasingly powerful weaponry.

There is a story buried in here too, though you'd be forgiven for considering it mostly irrelevant as text boxes flood your screen after every story mission, only to unlock more story and side-missions to earn more cash and experience for bigger and better weapons.

Once in a mission it's hard not to be overwhelmed by the slick 3D graphics that look absolutely resplendent on the iPhone 4S and latest iPads; gorgeous lighting, large levels that combine claustrophobic corridors and open areas that scream 'ambush', as well as detailed and smoothly animated enemies are all on show.

Unfortunately the rest of the game, notably the gameplay itself, feels like a hold over from twin-stick shooters - it's all shoot first, ask questions later and pray you get enough cash to upgrade your weapons to survive the next level. Grinding is certainly an option thanks to side-missions, though players can side-step the process thanks to IAP for 'gold', a resource that not only limits your firepower, but also how many weapons and items you can take on a mission, as well as boosts that can reduce their challenge.

It's not that this formula is inherently bad, it's just that it doesn't unlock greater depth or variety in the gameplay beyond giving you new toys and making life easier.

Beyond the presentation of new stages and the occasional new weapon, Dead Trigger lacks a compelling reason to keep coming back for more unless you enjoy slaughtering the undead wholesale.