Every game has a single over-riding requirement for its players. Some demand lightning-fast reflexes and the commitment it takes to master the depth of their controls. Others ask for a willingness to think outside the box or some degree of intelligence for puzzle solving.

These are all attributes players will need if they hope to succeed in The Elder Scrolls V: Skyrim. But the one asset players will need above all else is time.

The reason for this is that Skyrim is one of the most gargantuan undertakings gamers will experience all year. The sheer size of the adventure, both in terms of its environment and in the amount of activities available to the player, is mind-blowing.

This shouldn't come as too much of a surprise. The game's developer, Bethesda, has banked a rather lucrative existence on creating open-world RPGs that are filled to bursting with content. As with Elder Scrolls IV: Oblivion and Fallout 3 before it, Skyrim is a game that's easy to completely lose yourself in.

The reason for this is two-fold. First, the game's production values work hard to immerse the player in Bethesda's sword and sorcery world. For a game of this size the quality of the graphics and the attention to detail is awe-inspiring.

As the player travels through Skyrim, they'll encounter dense woodlands, snow-capped mountains, majestic cities and crystal clear rivers that run throughout the map. They'll run into an assortment of interesting characters and battle myriad monsters.

The Elder Scrolls V: Skyrim

They'll have to plough through blizzards, find shelter from thunderstorms and, on a clear night, they can gaze up at the sky and see auroras bleeding through the darkened heavens above them. The visual and sonic features of the game completely obliterate any traces of the outside world.

The second part of this enchantment is wrapped up in the number of ways Bethesda allows the players to interact with the world it has created.

Players can while away hours upon hours creating weapons at a forge, mixing potions at an alchemy table, enchanting weapons, chopping wood, practicing archery, investigating subterranean caverns or simply pointing their character at the horizon and heading over the nearest hill.

They can buy a house, join a guild, marry an NPC or read every book contained in the library at a college for mages. Around every corner and at every new town they wander into, there's a monster to fight, a character to talk to and some new discovery to be made.

The amount of things to do in Skyrim makes the player feel like they're a living, breathing part of its world. In short, you need time by the bucketload to get to grips with Skyrim, because once you enter its world, it becomes your world.

The Elder Scrolls V: Skyrim

There's a story, which guides the player's progress to an extent. It begins with an escape from the headsman's chopping block and then the player is cut loose in the massive world of Skyrim with the barest essentials in information about themselves and the land they now inhabit.

Skyrim is plagued on two fronts – by a bloody civil war and by the return of a race of dragons that, until recently, were extinct. The player is also aware that they are the last of a race called the Dragonborn, and they are also all that stands between Skyrim and its ultimate destruction.

Still, that's enough to be getting on with, eh? The plot then proceeds to reveal its pleasures by inches, one mission and side-quest at a time.

As the player completes one heroic (and not so heroic) deed after another, they get to grips with the game's deep and intuitive control system. The right and left triggers wield whatever weapon, shield or magic spell the player assigns to them. The inventory soon starts filling up with useful items that the player can assign to the D-pad for a quick weapon change act in the middle of combat.

Every time the player uses a weapon or a spell or skill in Skyrim, their profiency with that item or in that talent goes up. Once their overall XP hits the next level, they're able to assign a talent point to the skill of their choosing.

The Elder Scrolls V: Skyrim

In this way, the game rewards the participant for playing in exactly the way they want to. If you want cut your way through the land using just a sword and shield, the game will ensure you become more proficient in doing so. If magic or sneaking about in the dark are more your things, you'll get better at both the more you do them.

On top of weapons and spells, the player has an edge over most opponents in the form of their Dragonborn "shouts". These are magical powers that are acquired by reading runes carved into the walls of dungeons and caves the player will encounter, and which are unlocked with the souls of the dragons they've killed.

Shouts vary in power and recharge rate; one enables the player to breathe fire on opponents, another provides them with a quick-sprint, and yet another allows them to bring a dragon crashing down from the sky.

There's a price for all this power. Players will have to look past occasional bugs in the gameplay, for one.

These range from characters attaching themselves to pieces of the environment, the odd animation glitch and the rare instance where a previous save needs to be loaded after the game crashes completely.

There are also a couple of niggles that were present in Fallout 3, too, such as the unnerving stare plastered over the faces of NPCs or the way in which accidentally picking up an item that doesn't belong to you can cause a friendly character to turn hostile.

But the largest cost that Skyrim wishes to exact from players is that which is measured in human hours: time. And given the volume of content Bethesda's game holds, preparations ahead of playing may be necessary.

So, with that in mind, may your boss believe you when you phone in claiming you have the plague, may your significant other be tolerant and understanding, and may your friends know you well enough not to make enquiries with the police if they don't hear from you in over a month.

Skyrim awaits, adventurers. All it asks in return is your life …

… well, a large chunk of it anyway.

• Game reviewed on Xbox 360