At first, I wasn’t prepared to say that this unique puzzle game is particularly scary, but after I put the iPhone down and realised how badly my ice-white knuckles were cramping, it seems only fair to say that the atmosphere is one of fear and tension.

It will make you seriously think twice about playing Soul in the dark.

The title isn’t just a clever name. This game begins in an old, dilapidated hospital, with a dead body laid out on a mortuary slab. It’s easy to forgive the horror clichés once Soul gets moving, however, when a ball of hovering, accelerometer-controlled white light emerges from the corpse.

Guided toward the light

Taking control of this disembodied essence, your task is to guide the soul out of the darkness and into the light. Each level represents a dark and ominous maze, often illuminated only by your deceased traveller’s spirit.

Lurking in the shadows are vicious, snapping agents of The Beast, which attempt to force your path into the underworld. A steady hand is your only salvation. Combined with exquisitely crafted visuals that saturate the game with a sense of haunting and filth, the chills are both psychological and tangible.

The tilt controls are pretty critical as you wind your way around the hand-drawn horror environments, but a calibration feature is available at any time to make sure you’ve got complete control over your soul.

Stairway to heaven

Where the game stumbles a little is in its 'save' feature. Unless you make a manual save, your progress is lost. This wouldn’t be so bad until you get a phone call or need to switch apps on a moment’s notice, and considering some of the levels are as hard as they are frightening, the game can become annoyingly tough.

Yet, such genuine chills and moments of white-knuckle horror are incredibly rare in video games (and not just on iPhone) so anyone who likes a good scare should search their soul and stare into the abyss of this outstanding horror puzzler.