I'm all for a bit of realism in games, but from time to time I want fantasy. I want trolls, chupacabras, golems, massive titans, werewolves, vampires, undead freaks, fairies, mystical lands, gorgeous scenery, magic and over-the-top action. That, in a few words, is Castlevania: Lords of Shadow, the most epic hack 'n' slash adventure I've ever played, packed with the kind of dark fantasy that video games are perfect for. Despite being a relative unknown, developer Mercury Steam has outdone itself here, crafting a rip-roaring adventure that delights from start to finish.

Castlevania: Lords of Shadow (or CLOS as it will now be known) casts you as Gabriel Belmont, a member of the Brotherhood of Light. This knightly group protect the innocent from supernatural and undead creatures, roaming the land after the connection between the Earth and the Heavens was severed. An evil group known as the Lords of Shadow is behind all this, and it's up to Gabriel to save the world. With his wife falling at the hands of these evil creatures, his desire to rid them from the land is even greater, and a mysterious mask seems to hold the key to resurrecting the dead.

Several secondary cast members are introduced throughout the adventure, including mentor Zobek and man of the forest, Pan. Each character is surprisingly well developed, and one early twist had a real impact despite the character in question only being around for a few hours prior.

Whereas Castlevania is predominantly known as a 2D old-school action platformer, CLOS is in the God of War mould, complete with fixed camera, multiple button combo attacks, magic, puzzles and a little bit of platforming. Gabriel's main tool is his Combat Cross, which combined with a whip lets him perform directional and area-based attacks. Depending on the situation you can focus on one enemy or fend off a group by swinging the Cross around. A host of secondary weapons bulk up your combat options, with daggers taking down enemies from range, holy water making short work of vampires, fairies distracting foes and an incredibly cool crystal summoning one of the most deadly, evil-looking creatures I've ever seen.

While the weapons are at the core of the combat, the real depth lies in the use of Light and Dark magic. When activated, Light magic replenishes Gabriel's health as enemies are attacked, whereas Dark magic dishes out more damage per strike. Each can be upgraded to offer more moves and special attacks, but the fundamental idea is this balance between being the ultimate badass and making sure your health meter isn't about to run dry.

Magic requires neutral orbs, gained by defeating enemies or by attacking them with a full focus meter. This central bar fills as you fight enemies while avoiding being struck, with it returning to zero if you fail to dodge in time. Evading and counterattacking are absolutely essential if you're going to get anywhere in Lords of Shadow, as without them your Focus is never going to fill and you're not going earn the orbs needed to power your magic. If this sounds a little complicated, that's because it is. Like the Castlevania games before it, CLOS isn't afraid to dish out the pain, so don't expect an easy ride - especially on the two hardest difficulty settings.

It takes a while to click, but when it does the combat comes into its own, with the depth found in managing your magic equalling that found in the large move and combo set. Genre staples like hidden items that increase your health bar and magic meters are present and correct, as is an in-game currency (earned by solving puzzles) that can be used to buy new advanced moves.

Relics, generally obtained by defeating bosses, grant Gabriel even more abilities, such as boots that unlock a speedy run that enables him to leap further when jumping, and a gauntlet that allows him to perform ultra powerful punches. Mix everything with magic and there's even more to be found, such as powerful Dark magic-infused daggers and fairies that explode on impact when sent out under Light magic.

There's a smattering of QTE-like moments, but instead of having to hit the exact button, any will do as long as you press within the available window. Certain attacks end with a button being hammered over and over, but these aren't tricky, so you're never left cursing your slow fingers.

Boss battles are truly spectacular, with sizes ranging from just larger than Gabriel (himself a hulking man) to Titans so big they fill the entire screen and more. In some cases it's real Shadow of the Colossus stuff, with our hero climbing up the enemies and gripping on for dear life. There's just so much variety, both in standard enemies and in climactic encounters, that you wonder how on earth the dev team found the time to cram everything in.

Some might argue that the combat isn't as technical as that found in Bayonetta and Ninja Gaiden, but it's extremely satisfying and has depth in other ways. Fights against large groups of enemies and larger foes require real patience and clever use of magic or you'll find yourself returning to the last checkpoint over and over again.

An impressively in-depth combat and magic system would be for naught if the adventure wasn't worth going on, but CLOS tells an immense story that stretches across a good 15-20 hours, perhaps even more if you want to 100 per cent each of the game's stages. You'll fight in sewers, fantastical forests, ancient castles, decrepit graveyards and snow-covered mountains, with each locale looking as spectacular as the last. Whereas most games these days tend to wrap up after 7-8 hours, CLOS feels like it's just hitting its stride at that point. Not only does this mean the game offers extremely good value for money, but it adds weight to the story, with Gabriel's quest feeling like a proper arduous journey.

It's not all hacking and slashing, with a fair amount of puzzles, mounts (the less said about the frankly creepy giant spiders the better) and platforming, each able to match the quality seen throughout the title. Puzzles arrive in a decent variety of styles, but generally require you to move items into a certain position, or to trigger switches in the right order. Scrolls on nearby bodies reveal clues and, if you really can't work out the solution, offer you the solution if you forfeit your reward. The platforming, which feels like a slightly heavier version of Prince of Persia, sees Gabriel leaping about on platforms and ledges, while his whip allows him to abseil up and down walls.

If there's a slight weakness here, it comes from the mounts. They're undeniably cool to ride, but their use becomes a little predictable and repetitive. You'll enter an area only to come across a wall or door that you can't break through on your own. This is game-speak for "a massive beast is around the corner and you're going to need to tame it in order to progress". It's not bad, due to the combat being fun, but after a while the repeated use of this mechanic felt a little lazy - especially in the face of a game that is otherwise brimming with ideas and incredible imagination.

It's not that video games have never gone down this fantasy route before - they definitely have - but CLOS sets out so with such impressive art design that every new location, every quirky enemy, and each surprisingly boss fight is a real delight. There are a few technical issues with the presentation, namely a slightly jagged appearance and the odd frame rate stumble, but these are minor blemishes on an otherwise incredibly well-realised world. Fans of gothic art and director Guillermo del Toro are in for a real treat.

It's clear that Konami has grand plans for Castlevania - you only have to look at the list of talent voicing the game's key characters to see that. Gabriel is played quite superbly by Robert Carlyle, while Patrick Stewart is perfect as Zobek - his chapter intros always setting the scene wonderfully. Other characters Gabriel encounters along the way all benefit from equally professional voice work, and the stunning orchestral soundtrack knows just when it's needed.

Calling CLOS a surprise hit might be a little unfair, as the game looked impressive throughout development, but it's fair to say that I simply didn't expect to enjoy it this much. With a combat system that cleverly overcomes button mashing, wonderful design work and a story that spans far longer than your average video game, Lords of Shadow is exactly what the Castlevania franchise needed to find popularity with a new generation of gamers - and us oldies too.