One of the wonderful things about Japan is just how openly people express their love of video games. Old business men in suits sit on the Yamanote Line stooped over their Nintendo DS as they make their way to and from work. Trendy teenage girls hang about Harajuku Station huddled around wirelessly linked PSPs. There is no shame, no fear of being mugged.

What are they playing? Capcom's Monster Hunter, probably. Its popularity is almost single-handedly fuelling the PSP's astonishing success in Japan. Us Brits, we go down the pub or out clubbing in order to socialise. The Japanese form wireless parties and go off tracking down fantastical beasts. When a new version is released, Tokyo grinds to a halt as notorious otaku havens like Akihabara and Shinjuku are swamped by fans baying for Monster Hunter blood. They just can't get enough of it.

And yet it's never taken off in the UK. In fact, it's virtually non-existent. This is in part due to striking cultural differences, the geekiness still associated with boys and their toys in the West, as well as a genuine and understandable fear of getting mugged (you'd be a brave soul indeed to get your PSP out at a London bus stop). Gaming with friends in public has so far proved a marriage too difficult to maintain in good old Blighty. Japanese publisher Koei, however, reckons there's the potential for the get together and play portably concept to prove successful on these shores. And just to prove it, it's drafted in its hugely popular Dynasty Warriors franchise to get the job done.

The result is Dynasty Warriors: Strikeforce, due out on the PSP this May. It's a game that retains much of what fans love of the series - famous Chinese warriors cutting thousands of enemies to ribbons in (loosely) historical battles lifted from the country's rich history. But it's also a game that brings something new to the table. Strikeforce is Dynasty Warriors remoulded, re-jigged and repositioned. It is the bastard child of Dynasty Warriors and Monster Hunter, with a late claim for custody from Phantasy Star Online.

The gameplay has been tweaked to echo Phantasy Star Online's party-based play

While the classic ancient Chine setting and generous roster of historical warriors have been left well alone, the gameplay has been completely revamped. The huge, often hour-long levels that have underpinned the Dynasty Warriors experience have been dumped in favour of tightly focused dungeon crawling missions that shouldn't last longer than 20 minutes. For the first time in a Warriors game you can lock on to enemies and use ranged weapons in third person. Strikeforce feels more like an old fashioned shoot-em-up than it does monotonous hack and slash.

The new Fury Transformation mode makes the classic, enemy-clearing Musou attack more of a rarity than it has been in the past. Now, as your Fury bar fills, every aspect of your character upgrades, from speed to attack power to dash. Only when it's completely full will you be able to do the Musou attack. Simply spamming a single button is no longer good enough to get by.

It's in the structure of the gameplay that the Phantasy Star Online influence is felt strongest. This owes much to the new focus on four-player team play. There are less enemies, perhaps unavoidable given that the game is on the PSP, but Koei insists they're much more intelligent. It's all about teamwork, about each player playing to their character's strengths. From one of the game's town square hubs, based on ancient Chinese towns themselves, you and your wirelessly connected pals can group up and embark on an available mission. You work your way through a number of mobs, occasionally interacting with the environment (in part of a snow level constantly spawning tigers can be trapped by closing cages) until an impressive boss with loads of hit points is reached. It's then up to each member of the group to fulfil a certain role - tank, heal, nuke, crowd control, that sort of thing - until it's down and the loot spills out into your grateful inventory. Then it's back to the town square hub for trading and upgrading.

Orbs and Chi can be attached to each arm and leg, granting your character special abilities. For the first time in a Dynasty Warriors game you'll be able to fly, the result of combining jumping with the float ability. When you meet enemies who can do the same, expect Crouching Tiger Hidden Dragon style scraps as swords clash in mid-air. You can even have your character use any created weapon - another first for the series.

The graphics are great, certainly up there with the best on the PSP.

The upgrading isn't limited to your character - the town squares have five levels to work through. You'll be able to show them off as well. Hosts can allow other players to come into their town so they can marvel at just how hardcore you are. You can even send items to your friends, who can save them to a memory stick.

The re-jigged, PSO-influenced gameplay is complimented by some brilliant graphics. Other than Ready at Dawn's tremendous God of War: Chains of Olympus and Square Enix's Crisis Core: Final Fantasy VII, we can't think of many PSP titles that look more impressive. Anyone looking for an action game to show off that gorgeous PSP screen need look no further.

It seems a crying shame that you won't be able to go online with Strikeforce. That means that if you want to play it as it's meant to be played you'll have to find some mates who want to do the same, something that might prove to be a challenge in the UK. Perhaps with this in mind Koei has promised it'll organise gatherings where people can play together safe from the prying eyes of those who might rob you blind. It's not exactly how they do it in Japan, but it's a start.

Dynasty Warriors: Strikeforce is due out on PSP in early May.