Upon dying for what felt like the sixth millionth time, to a lowly boss in the middle-sections of Demon's Souls, I genuinely felt like running the disc through a shredder, crawling under a table and sobbing in the foetal position. This is a cult title by curious Japanese developer From Software, a studio most recognised for the Armoured Core series, though I will always remember them for 2004's Metal Wolf Chaos - a game which featured the president of the USA climbing aboard his giant mech and quelling a coup d'état. Demon's Souls, however, is a vicious, bleak and painfully difficult action RPG, and it just so happens to be one of the PS3's finest exclusives to boot.

You kit a lone warrior out with all kinds of spangly loot and have them hack their way through (or, more likely, get slaughtered by) shuffling zombies, run-of-the-mill soldiers, creepy leaping skeletons, glowing octopus-esque mind flayers, oily black blobs of evil goop armed with shields and, while you're at it, a spooky nun. This is all done while plodding through some of the darkest and dingiest video game environments created since the original Diablo, with the game encouraging you to turn the brightness down to a level only an owl could possibly feel comfortable moving about in.

It's a methodical game, and even though there's a run button you'll rarely sprint into the unknown because something horrible will probably jump out and lop your head off. Disillusionment can (and probably will) seep in fairly early on, as the game chucks you into a brief tutorial sequence only to brutally murder you as soon as you're starting to feel like you understand with what's going on. The moral of the story is that you will never, ever feel comfortable playing Demon's Souls.

Death is frequent and terrifying but never the end, as you simply respawn at the start of the stage, albeit in a spirit form where health is reduced to half of your maximum. In practice it's more like three-quarters, though, as you're given a health boost if you equip a magical ring found in the corner of the very first level that you should absolutely, definitely and positively pick up before you do anything else.

The only way to get back into your physical body is to slay one of the 22 boss monsters - and they don't respawn, either, so you can't even go back and clear out an early level to reclaim possession of your flesh and organs. You can, however, reclaim your physical form by allowing yourself to be summoned into another player's game to help them tackle a boss.

Or, instead, you can just be a bit of a knob and jump into random games to chase people around a bit - though doing stuff like this gives the game a tendency to throw bigger, nastier monsters in your direction later on.

The whole process can be mortifying, and spending ten minutes fighting tooth-and-nail against some gnarly boss beastie, only to have it zap your entire health bar in one hit, can have a devastating knock on your psyche. That's the rock bottom moment for Demon's Souls, but you'll be feeling it far too often for comfort.

Your only sanctuary is provided by the Nexus, a mystical hub world which features two floors of dead half-human marionette torsos, apart from a single survivor who instructs you of your mission to slay evil and give a Devil-like figure a jolly good shoeing. Like the rest of the game, the Nexus is an elaborate construction of Medieval-inspired architecture peppered with twisting staircases, crumbling walls and not nearly enough light sources. The Havok physics engine can mess with the otherwise pitch-perfect atmosphere, however, with enemies tumbling around beneath your feet like crisp autumnal leaves.

While the magnificent and ornate boss encounters will provide the most severe test of your mettle, even lowly monsters can ship you back to the start of the level if you're careless. Successfully kill a baddie and you'll pick up a few souls for your efforts - these double up as both the in-game monetary and levelling currency. The game provides you a convenient item bank from the offset, but there's no way to store your precious souls. If you die (and you will) the game robs you of the souls in your possession, which is like kicking someone when they're down.

Find your bloodstain, left at the location of your demise, and you'll be able to recover the souls you lost; die again before reaching it and you can wave them goodbye. The game's greatest accomplishment is in the way it creates a lingering sense of unease and dread, and when you actually manage to reclaim your body you'll find yourself clinging onto it for dear life, tentatively creeping around corners and rarely lowering your shield. Your instinct is always to stay in the safety of light, though that's extremely difficult for a game perpetually shrouded in darkness. Eventually, you'll accept that death is part of the process - and you don't lose any of your items for popping your clogs, either.

At the beginning of the game you pick a starting class - soldier, hunter, thief etc. - though these are more like guidelines than rigid templates: stats can be funnelled into any area you wish, and no class is denied access to any of the game's equipment. Most of us will just pick the knight anyway, as he looks awesome and is on the front cover of the box.

Combat is weighty and dangerous, and it's important to only swing your weapon when you know you're going to land a hit. It sounds easy on paper, but only after spending a few hours with Demon's Souls do you realise how forgiving others games are when it comes to liberal bouts of manic button-tapping. It feels comparable to the fighting in Monster Hunter, though far more precise (there's a lock-on feature, which is nice) and significantly less exaggerated.

There's also a bevy of spells and miracles to learn if you're magically inclined, such as being able to conjure up clouds of plague and acid, a shield of water and bolts of fire. Both magic and weapons are grounded, restrained and lacking in theatricality, which leaves you to instead focus on the sense of enormous satisfaction you'll get from sorting out a pesky Red Knight that's been giving you trouble a week.

Walking the path of Demon's Souls is a lonely road, and while the game includes a suite of unique online features it's very much geared towards solitary play. You are given no control over who you bump into on the journey, meaning you're stuck accepting the fleeting help of strangers instead of the warm, reliable companionship of close friends. Wispy shadows of other players follow you around as you play, and you can leave a selection of messages on the ground for others to see. or. It's worth reading the notes left by others doing, too: if another player recommends your message then your health is immediately restored.

Demon's Souls is a pitch-perfect example of how great risk can make the rewards taste all the sweeter. Getting killed in a single hit from a multi-storey, frog-like monster with a giant meat cleaver and a thirty-foot tongue is always going to be frustrating, but persevere and a couple of weeks later you'll be wondering how he ever bothered you. Demon's Souls pits you against your own incompetence and inexperience, a challenge which often feels insurmountable, but that delivers some incredibly powerful thrills for players brave enough to commit.