It's not too often you get to be eyewitness to a top MMO in decline but thanks to World of Warcraft's users dropping with the kind of fervour usually reserved for the X Factor's viewing figures it's finally possible. Seven years ago when World of Warcraft was first in its prime we saw a rise in clones that took their cues directly from the working model Blizzard had created. But its inability to keep players interested forever has meant in the last year we've been able to see clutches of games emerge with a distinctly anti-WoW methodology. The Secret World sits somewhere near the top of this pile as an MMO that is nearing its release date with as little of Warcraft in its genetic code as possible.

If you're a Funcom aficionado you might be familiar with their adventure game series The Longest Journey, or even Anarchy Online - the studio's very first MMO from ten year's back. Imagine an amalgamation of the two and you start to get a firmer picture of The Secret World. It takes the structure of an MMO, but in terms of in-game content Secret World has cultivated a puzzle-riddled ethos closer to what you'd find in adventure games of yore.

That's because for all intents and purposes, The Secret World is a mystery game. The "Everything is True" tagline used throughout its marketing campaign is Funcom waxing philosophical about what would happen if a real person were to co-exist with all the monsters our parents told us weren't real. The studio's answer is to reproduce real-world cities - London, Seoul, New York City, Egypt, and so on - and introduce a seedy undergrowth of monsters that sit comfortably next to anything out of Lovecraft, Romero, or American Werewolf in London. And while you'll fight them along the way, a chunk of the game is dedicated to just investigating some of the overarching conspiracies they're involved in.

There are secret societies, references to chaos theory, alongside group instances against Cthulhu-alikes who transport you into the veil and back into reality again. It's a scattershot approach to the world of conspiracies in a way that should feel familiar to anyone who enjoys the "everything but the kitchen sink" mentality Assassin's Creed has about its own allusions to conspiracies. But the game stays focused enough to carry that kind of referential weight around.

Tying it all together are the secret societies who, even in the real world, have both feet firmly planted in conspiracies. You play a member of one of these three secret factions trying to gain control of the world: the New York-based Illuminati, the London-based Templars, and the Seoul-based Dragons. Each of them have hide-outs tucked away in their individual cities, next to pubs, record stores, and Top Shop-alikes that you can explore at some degree like a real-life tourist. But generally speaking they work with one another trying to get over the next incoming hurdle of monsters.

The game doesn't include levels or classes - one of the main features The Secret World has cut out of WoW's mould. Instead what you get is a system where players earn points through kills, missions, crafting, and so on, which can be plugged directly into skills. Rather than traditional classes, you'll create what's ostensibly a "deck" made of seven active and seven passive skills that can be switched out for any other available skill at any point. You're given three weapon types as well, Magic, Melee, and Ranged - the latter which includes semi-automatic rifles - but like its skills system your avatar isn't bound to one specific play-style and it's possible to re-spec on the fly.

While a third of the quest-types available are of the "Kill 10 X" ilk, the game isn't particularly built for old-fashioned grinding. Unlike most MMOs, Secret World enforces a certain amount of pacing. You can only hold a few quests at a time, and rather than handing them back in to NPCs you'll often only need to press a button to send them in as "reports".

Similarly, you won't just skim over missions. Each quest-giving NPC is accompanied by their own individual cutscene, which is a feature worth pointing out if only because this game's narrative-bend has been overshadowed by The Old Republic's in terms of how the two have been advertised. It's also worth pointing out that so far The Secret World's NPC cutscenes are already more engaging than The Old Republic's in terms of script and character personality - something that ought to prove important to narrative fans. For all of its gothic leanings, the game is funny, strange, and easily one of the most distinctive MMOs of the last ten years.

It's arguably an even more ambitious project than The Old Republic is, too, but that doesn't always work in its favour.

Often the game's too preoccupied with being a post-WoW MMO, and that results in some unruly quests. Some of these, oddly, tip their hat to gameplay styles last seen in the point-and-click genre, back when you could solve a puzzle by sweeping your cursor over the entire surface area of your screen to find hidden objects. These "Find X" quests have you search across rooms, rooftops, or entire streets for objects ranging from phonebooks to pieces of paper, but like point-and-clicks of the past they often confuse challenging game design with the simple frustrations that come from pixel-hunting.

The MMO's biggest challenge is how often its innovations are coupled with difficulties at a design level. At its most ambitious, its Investigation Missions are designed for users to solve them using real-world tools like Google to research clues - an idea adopted from alternate reality games which themselves blur the line between game fiction and reality. In these quests, players are given a piece of obscure prose that might reference a famous figure or a passage from the Bible. With that they're encouraged to Google information relating to the clue, in order to work out where exactly to go in-game. Elsewhere these clues will relate to data the player is asked to type in to a computer terminal using basic DOS commands.

Funcom has plans to include an in-game browser similar to what we've seen in EVE Online, but how well this will really work relies as much on the game's player-base as it will on Google and some decent programming. Can users who in all likelihood are coming from a traditional WoW background be expected to crack codes and word puzzles? The studio has until April to work that out, which makes it easily the most ambitious - and honestly exciting - MMOs set to release next year.