Did you know there is an amusing Metal Gear Solid cameo in Assassin's Creed: Brotherhood? It's an apt inclusion really, because while it can't quite hold a candle to the eccentricities and convolutions of Hideo Kojima's labyrinthine stealth-action saga, Assassin's Creed is certainly getting there.
Let's recap. You are a man named Desmond Miles, who spends most of his days strapped to a machine called the Animus. The Animus lets Desmond relive the genetic memories of his ancestors, who happen to be an order of Assassins, locked for millennia in a struggle against the naughty Templars who want to subjugate humanity for the greater good.
Desmond was first captured by the Templars, who wanted to use him to find the legendary Pieces of Eden, objects of unspeakable power and potentially otherworldly origin. But he was snatched up by present-day Assassins... who wanted to use him to find the legendary Pieces of Eden so the Templars couldn't get their hands on them.
But you really spend the majority of the games dealing with his ancestors - in the first it was Altair, who ran amok across the Middle East taking out influential Templars before it turned out his boss was a bit shady. Assassin's Creed II gave us the charismatic Ezio Auditore, who journeyed around Renaissance Italy avenging his murdered father and eventually confronting the Templars responsible and - spoiler - becoming a vessel for communication between the source of the Pieces of Eden and Desmond in the present day.
It all sounds rather simple when you put it like that, which is probably why the games never did put it like that. Instead, they conveyed it through a mixture of elaborate sermons from key characters, clues and mysteries in the environment, and good old-fashioned voice-overs from Desmond's support team.
All of which left us at a tantalising and pivotal stage when the curtain fell on Assassin's Creed II. What we really wanted was the next chapter. Brotherhood, which is not Assassin's Creed III, has the unenviable task of delivering on a promise it's not really designed to keep.
But enough "previously on Assassin's Creed" - not least because Brotherhood picks up where its predecessor left off in more ways than we had dared to hope. Ezio returns to Rome in full this time, rather than just invading the Vatican, and discovers that it is not only rife with his enemies the Borgia - key Templars of the era - but as vast and magnificent as the cities of Assassin's Creed II put together.
We also get to see more of what Desmond and the Scooby gang of modern Assassins he hangs around with are up to, and while marginally less dramatic than the previous instalment, revelations outside the Animus remain artful and carefully managed, rich in mystery and fan service.
But of course you spend most of your time inside the Animus, and it has never been so pleasurable to be there, using Ezio's parkour and combat skills to convey him fluidly over complex terrain. Impatient players will snag and falter now and again, but several additions - quick-release rope-lifts, horse-riding within cities and kill-streaks that let you segue stylishly between one-button executions - polish an already experienced move set to a shine.
Assassin's Creed II gave you many fun things to do and items to collect, and Brotherhood intensifies this so that your trusty map is a forest of icons within a few opening hours (much better opening hours, incidentally). The real revelation, though, is what those icons represent. Brotherhood's conceit is that you are trying to liberate Rome, but the manner in which you do this is contrived in ways that play perfectly to the series' strengths.
There are Borgia Towers, for instance, which hold influence over areas of the city, and each is a free-form assassination task where you must isolate and kill the local Borgia Captain under the noses of his men. Each is unique and many are thoughtful and memorable, some more so than the nine assassinations that formed the spine of the first game - a demonstration of how far the series has come in just three years.
With the fall of each Borgia Tower you can renovate surrounding shops and facilities, providing a regular income at convenient banks - money which you can then sink into further renovations and upgrades to your arsenal, creating a virtuous cycle across the city that illustrates your growing influence.
You can also recruit members of the populace and train them as assassins, sending them on missions around the world to sharpen their skills and calling on them in battle. Highlighting an enemy, pressing a button and watching a herald of angelic forms descend unseen from nearby rooftops to perform silent, brutal assassinations in your stead never grows old.
Midway through the game you meet an old friend who puts you on the trail of some nasty new Templar weaponry, and each of these quests takes in a self-contained stealth mission followed by an action sequence, isolating and enhancing other areas of the Ezio toolbox to similarly positive effect.
Clearly having learned from the city-building sections of the second game, Brotherhood also expands on the excellent Assassin's Tomb platform levels, sending you into the lairs of the followers of Romulus, some of which are masterful and change the pace of the game in the process. One in particular - a silent, practically greyscale exploration of a ruined basilica - would have Lara Croft weeping with nostalgia.
These diversions are always tied back into the core quest, which itself is very creative and supported by strong acting. One mission sees Ezio disrupting an assassination attempt in the ruins of the Roman Colosseum during a play about the death of Jesus Christ. It demands a developer of poise and compassion to wield such thorny concepts deftly, and it's a measure of Ubisoft Montreal's maturity that it is more than equal to the challenge.
Never before have we seen a game whose open world is so densely packed with things to do while maintaining such high quality. Whatever your particular taste, you simply cannot run from one area to another without encountering something else that you want to stop and do. Thanks to the Animus, which frees the developer to break the fourth wall at will, Brotherhood builds an intriguing mystery around compelling characters, surrounds them with collectibles and secrets, and encourages play - and nothing feels out of place.
The game's richness does mean that it suffers slightly from overexposure. Played at a reasonable pace, you can overlook the simplicity of the empire-building, along with the infrequent difficulty spikes that force you back to the last checkpoint. But in a game that seems designed to be greedily and intensively consumed, they are faults that matter.
Outside the campaign, Ubisoft's Annecy team has contributed a matching multiplayer component with four modes. In Wanted, Alliance and Advanced Wanted, you are given a picture of your target and a vague radar indication of where they are, while another player is given your image. It's kill or be killed. Just don't kill the wrong person.
Set within the Animus to justify the use of identikit NPC models, the result is that you're never sure who is stalking you, so you have to watch carefully to see who betrays themselves through their actions. In Advanced Wanted in particular - and also Manhunt, where players are split into teams of assassins and prey - identifying targets is satisfying, and skilful anonymity is richly rewarded.
There is a levelling system, and while it is impossible to gauge over just a few hours of pre-release play how well this aspect of Brotherhood will endure, multiplayer feels gripping and unusual, if not especially deep. It should extend the life of a game that already runs to 20 hours should you choose to rinse it thoroughly.
And choose to do so you almost certainly will, because Assassin's Creed: Brotherhood is a masterful combination of the many things that have striven to define the series in the past, each presented at its best and accentuated by considered design.
Should you need to retrace your steps to climb back up after a fall, for instance, you frequently discover a loot box stuffed with treats at the foot of the nearest convenient ladder. Ubisoft has tinkered with rewarding failure before, notably in the 2008 Prince of Persia reboot - but as with much of the rest of the game, Brotherhood presents a simple, elegant solution almost effortlessly.
It's one of many finishing touches to a game that started life as what sounded suspiciously like a fund-raising stopgap conceived on the back of an overdrawn chequebook and blurted out during a conference call. Assassin's Creed: Brotherhood is anything but that, however - it's one of the best games of 2010.
10 / 10