Having touched a nerve last year with its turn-based strategy hit Hero Academy, Robot Entertainment has returned to the iOS battleground with a new game in tow. Obviously keen to try their hand at a combat system with more immediacy than Hero Academy's asynchronous duels, the team has knocked up a a sci-fi-flavoured action-RPG. Here, the combat is real time, and your enemies' feet aren't rooted to tiles on the floor.

You take control of a space-marine type who has been charged with barrelling around the universe and mashing up aliens with his laser sword. Each mission takes place inside an enemy spacecraft. To move, you simply tap or hold where you want your marine to run. Firing your blaster is as simple as tapping on an enemy. Get in close, and you'll be able to do damage with your sword.

As the enemy count rises and you begin to get overwhelmed by aliens, tactics become increasingly important. Foes with swords are best dealt with laser fire from a distance. Riflemen demand you master the swipe-and-dodge maneouvre, and get within swiping distance for a quick dispatch.

Echo Prime's unique feature are the Echoes themselves. These mystical creatures watch over your character from another dimension, granting you perks and power-up which can be used during scuffles. There are over 60 to collect and utilise, with skills ranging from health restoration to powerful elemental attacks.

As you can swap your Echoes around before every mission, you're often experimenting with new powers, which helps to break up the slightly hum-drum fighting. After a while, though, the levels do being to bleed into one long corridor. You do run in to some big bosses, and can spend cash upgrading your weapons and armour to boost your stats. However, while cracking alien skulls is fun in short doses, long sessions do devolve into slightly wearisome tap-fests.

If you're after a good-looking action RPG with a mystical slant to attack for 15 minutes here and there, then Echo Prime is a decent candidate. The Echoes are a neat hook, and the ability to borrow them from other players brings a welcome social aspect to every fight. We're not sure if the combat is compulsive enough to sustain you to the end of the campaign, though.