Monster Hunter Tri is an anomaly, a freak of nature, an exception to the rules. If it were a monster, it'd be an amazingly rare kind of beastie that hides in the darkest, dankest spots of Bodmin Moor. One lonely winter night you're out walking your dog; you hear a strange noise, turn - and there it is. "OMFG!" you gurgle. "WTF is that?" Then it'd bite your head off, claw open your twitching belly, and turn your entrails into some kind of funky hat. Meow.

Monster Hunter Tri is an anomaly for many reasons. For a start, it looks great. Sometimes people will describe a new release as looking "pretty good for a Wii game", much in the same way you might discuss a swimmer who "does pretty well for a chap with no legs". Tri is a genuine beaut, boasting detailed character models and a broad selection of huge, well-animated creatures to battle. But that's not the only point of difference between this and your average Wii release: motion controls are all but ignored, so much so that at this week's press event Nintendo and Capcom had decked out all the test consoles with the new revamped Classic Controllers. Finally, and perhaps most importantly of all, Monster Hunter Tri is a seriously hardcore game.

Long-term fans of the MH series will be all too aware of this last point. This isn't your average casual-friendly waggle-fest we're talking about here: Monster Hunter is a ballsy great hulk of a challenge, the kind of game where you can exhaust yourself for the best part of an hour, only to be suddenly crushed by a charging, teethy meat-tank. It's a brutal endeavour, and that's just what the veteran players like. The million dollar question is this: can the game find a broader audience here in the UK, beyond the small (but admittedly very dedicated) fanbase that already exists?

Only time will tell, but what I can say right now is that Monster Hunter Tri has the potential to be one of the best Wii releases of 2010. As with the previous entries in the series, the basic setup here is that you're a young warrior whose job it is to track and hunt down dangerous monsters (hence the title, durrr!). In this case, you've been specifically tasked with finding the creature that's been causing earthquakes around Moga Village - the quiet little village that acts as your hub between assignments. When you're not out trying to slay some towering mass of spines and fangs, you'll be able to explore Moga, chat to the locals (who also act as quest dispensers), sell the loot you've harvested from dead monsters and pick up new equipment. You'll also get to hang out at your snazzy-looking, open-plan shack - a cosy home that comes complete with a set of cat-like servants; these little feline chaps will undertake various tasks for you, including taking care of your own private garden, which can help to provide you with useful plants.

As it happens, you'll only be spending time in Moga in the single-player game. In another significant departure from standard Wii form, Monster Hunter Tri will have a significant focus on multiplayer action. There's an offline, split-screen mode called Team Takedown, in which you and a chum attempt to take down a specified monster within a confined arena, but the real draw here is the "true" co-op multiplayer experience over a network connection, wherein up to four hunters can head out on quests together. In this mode you start out in the stony city of Loc Lac, in a gathering hall where you can hang and chat with other hunters. The game's original Japanese release was restricted to text-based chat here, but the Western version will feature full support for WiiSpeak - allowing you to make friends, discuss tactics, or simply hurl torrents of abuse at your partners when things inevitably go pear-shaped.

Tri is the first Monster Hunter game to feature undewater battles.

However you choose to enter the fray, the core action remains pretty much the same: find your monstrous quarry and then attempt to take them down. The size of the animal in question can vary enormously, but whether you're fighting Jaggi (fierce and speedy, raptor-like lizards) or a colossal Barroth (a tough-as-nails, armour-plated T-Rex thing), the hunt itself will usually resemble a sort of drawn-out boss battle. There are a whopping seven different weapon classes to use, each with their own variants and tactics: the basic sword & shield combo affords you speed and manoeuvrability, but at the cost of power, while larger weapons like hammers and great swords allow you to hit harder, but slower. Bowguns allow players to snipe at foes from a distance with different ammo types, while the new switchaxe is a fearsome hunk of metal that can morph back and forth between two different shapes - a sword form, and an axe form. There's a strategic variety to your choice of arms, and that's before you even get into the various traps and items you can carry.

Technical depth aside, it's clear that the monsters themselves are the real stars of the show. As I've already said, there's an impressive level of detail to the creatures' appearance and the way they move, but it goes beyond that. Capcom has attempted to make its menagerie as lifelike and believable as possible, and the theory is that to defeat your opponents you'll have to know them inside out. Some monsters will fiercely protect their territory, for example, attacking any other lifeform that enters its vicinity. Others will flee after taking a certain amount of damage - not a problem if you're fighting in the arena, but if you're on an open map you may have to chase your enemy and finish him off before he manages to feed and heal himself.

Of the new creations on display this week, my clear favourite was a hopping green bird by the name of Qurupeco. After being smacked around for a bit, he'd puff up the large red sac under his beak and let out a loud call, mimicking the cry of another monster; a few moments later the monster in question would show up and enter the battle. Once again, this mechanic underlines the advantages to be gained from a solid knowledge of the monsters (and by extension, the game itself). If you can recognise the call Qurupecu is making, you might be able to predict who's about to join the party. Of course, it would be better still if you could just murder Qurupeco before he can open his gob, but then battles in Monster Hunter rarely go that smoothly.

This difficulty may well be Tri's stumbling block as far as mainstream success goes. Hardcore fans would baulk at a diluted game, but the fact remains that Monster Hunter is an intimidating experience for newcomers. Battles can drag on for a long time, particularly in the early stages when you're still getting a feel for things, and since there's no health bar for your monstrous opposition, you're forced to rely upon visual clues to how you're doing. The controls on the classic handset felt a little fiddly at first, but feel like they'd be easy enough to deal with over time - it's more the general level of challenge that feels like a tall order. On the other hand, there's an immense feeling of satisfaction you get when you take down something large. One demo at this week's event allowed players to try a four-man battle against a Lagiacrus, a giant-sized sea dragon, who can be fought underwater, as well as on dry land. When you're swimming in and out of submerged rocks, slashing away at a scaly leviathan, blood swirling in the water, it's hard not to get caught up in proceedings.

And prosaic though it may be to say, the Wii seems to handle all the technical demands without a hitch. The textures are finely detailed, the game worlds are sizeable and there can be loads of things going on at once, but Nintendo's little white box rarely seems troubled; only the frequent appearance of loading screens gives any indication of the weight on the console's shoulders, and these pauses rarely last longer than five or six seconds. Monster Hunter Tri looks like it could well be a bit of a treat, albeit a treat with an acquired taste. The Japanese release picked up lots of glowing words and high scores - including a rare 40 out of 40 from Famitsu - so it'll be interesting to see how the final game fares over here when it creeps out of its cave in April. Naturally we'll be tracking it down for ourselves, so check back here at Easter for a final verdict.

Monster Hunter Tri will be released on Wii in April 2010