Despite FEAR being a frequent patron to preview pages since it was first announced just over 12 months ago, the game's storyline has managed to remain hidden behind an almost impenetrable veil of mystery.

But now, after working our way through the paranormal first-person shooter's opening four missions, we've managed to uncover some plot details, while witnessing the unnerving atmosphere for ourselves.

FEAR's protagonist is a rookie recruit in the First Encounter Assault Recon (a special unit charged with combating paranormal threats to US security) whose principle objective is to locate and apprehend the psychic commander of an army of clones, Paxton Fettel.

The opening levels are wonderfully paced, relinquishing the sparsest titbits of information while cunningly drawing the player deeper into the action by introducing new avenues of chilling intrigue and amplifying the nervy atmosphere with subtle scare tactics.

Disturbing flashbacks, eerie apparitions and flickering lights all help to convey the presence of some unseen and other worldly enemy, which is quite an achievement for a piece of coding.

Of course, being a FPS there are some very real enemies to shoot and - in the first four levels at least - these come in the form of Fettel's clones.

These are, for all intents and purposes, pretty much regular soldier cannon fodder, although smart AI makes the set-piece skirmishes incredibly challenging.

To battle Fettel's foot soldiers a selection of weaponry is available and includes all the usual killamajigs, such as assault rifle, sub-machine gun and frag grenade, as well as some new, fancy-pants shooters.

A nail gun fires large stakes and can be used to impale and pin an enemy to a wall, while a particle weapon vaporises the flesh and literally rips the skeleton from an enemy's body.

In addition to a healthy arsenal of weaponry, there's a slow-mo function that can be used at any point, just so long as there's some juice in the auto-replenishing slow-mo meter.

This temporal tampering works incredibly well and, thankfully, feels like an intelligent and incredibly useful complimentary weapon, as opposed to a poorly implemented gimmick thrown in just for the sake of it.

Besides looking good, and boasting some great physics and impressive visual effects, FEAR has a carefully constructed and very tangible atmosphere that is both unsettling and absorbing.

And, although our 90-minute hands-on didn't reveal as much as we'd hoped it would, it certainly left us anxious for more and reinforced our initial inkling that FEAR should be something a bit special.

FEAR will be released for PC in autumn 2005