Like the mutated viral strains that inhabit its many undead bodies, Resident Evil keeps adapting. As a result, each new game has to ponder the past, present and future of the series. Should the next Resident Evil be survival horror? Should it be modern-style action? Should the camera really been so fascinated by ladies' bums?

Resident Evil: Revelations, the fourth handheld outing for the series, only knows how to answer that last question: and on that front (or rear?), it's a resounding yes. Other decisions are thrust onto the cartridge with less conviction. Unable to choose between the balls-out action of Resident Evil 5 and the classic tension of the original games, Capcom settles on a haphazard combination of styles that never quite works.

Much of Revelations takes place aboard the Queen Zenobia, a luxury cruise liner that resembles the original Resident Evil's iconic Spencer estate mixed with The Crystal Maze's Ocean zone.

The Queen Zenobia - designed by George Trevor, for fans of the series' tangled lore - originally recalls all that is cherished about the series' vintage titles: ornate architecture, gentle puzzling, and the back-and-forth traversal of an unwinding map as your inventory swells with an abundance of keys, security cards and elaborate trinkets. Interspersed with these engaging moments, however, are rote action sequences across bland environments. Trekking through some snow shooting mutant dogs feels like playing a limp version of John Carpenter's The Thing, for instance.

Surprisingly, Revelations' faults are not due to its technology, and the power of Capcom's MT Framework Mobile is nothing short of phenomenal, effectively realising the dream of bringing a console-like experience to Nintendo's handheld. Even the stiff controls are perfectly adequate, though its creators have finally bucked and added a strafe option which unwittingly robs Revelations of the series' most frequent scares.

While the game supports Nintendo's new Circle Pad Pro attachment for dual-stick aiming, the game's sans-Pro configuration switches between movement and aiming when your gun is drawn, effectively emulating the series' control scheme post-Resident Evil 4. The game's default setting has you aiming and firing your weapons in first-person, however, and while this makes targeting individual enemies easier, it can be switched to the series' more traditional third-person (and its inherently greater awareness of your periphery) via the options menu.

Conserving ammo is vital, as always, but inventory management has been scaled completely back. Boxes are now used solely to swap and upgrade weapons with the game's mix-and-match tinkering system, and any weapon left behind (you can only carry three at once) when out in the world will magically reappear in storage. It's also impossible to stockpile green herbs, as you're given a maximum limit of five at any one time. These changes make Revelations more manageable, which is perhaps what you'd want on a handheld device, but they also can't help but rob it of some of the series' tension and colour.

Without having to fuss around with a complicated inventory, an extra layer of fiddliness was clearly required. Enter the Genesis, a scanner lifted so brazenly from Metroid Prime it's probably got Samus Aran's fingerprints on it. Attempting to scan monsters while they're trying to eat your face adds a layer of tension, but it's too bad the rewards don't justify the effort. Every time an in-game ticker hits 100% the game chucks you a green herb, which half the time you won't even need. Something more akin to BioShock's photography would have been far more encouraging.

The biggest setback is structural. Wedged between Resident Evil 4 and 5, the game presents a fractured narrative that flicks between multiple BSAA characters - though mainstay heroine Jill Valentine takes lead role, with Chris 'balloon-biceps' Redfield headlining the supporting cast. Jill is joined by new sidekick Parker (who is a bit chubby; I imagine his nickname at school was Porker) while Chris is matched up with the voluptuous Jessica Sherawat, who is extremely annoying and sports what is quite possibly the most inexplicable and ludicrously revealing wetsuit in the whole of human existence.

They're all banding together to fight the T-Abyss virus, a peculiarly naval strain of the ever-reliable T-Virus, designed by naughty terrorist faction Veltro. T-Abyss causes humans to turn into pale spiky monsters whose heads split open to reveal phallic-like objects with mouths on them; it's quite hard to take the game seriously when you're being attacked by massive head willies.

The game's lowest ebb comes in the form of Quint and Keith - who christen themselves with the codenames Grinder and Jackass, despite no other member of the BSAA using a cryptonym - a supposed comedy duo who intersperse their tedious section with idle chatter about stalking women and vintage horror movies. It's teeth-grindingly bad stuff - a QTE sequence where Barry Burton fries eggs and watches pornography would have been less jarring.

It's occasionally possible to forget about all this chaff and padding when you're inching your way through the Queen Zenobia's claustrophobic confines, but the game never lets you settle in its highlights - promptly tearing you out time and time again for yet another silly ammo-blasting sequence where you stick your back to the nearest wall and hold down fire until everything has died, or another gut-curdling cutscene directed by someone who's been watching too much 24.

Outside of the lengthy 12-chapter campaign, Raid takes the role of the series' now-mandatory bonus mode, which has one or two players schlepping through 40 single-player environs and boshing away at new configurations of undead hordes, who now sport health bars and status buffs. Grinding through these levels gives you access to a shop where you can upgrade your weaponry, but Raid doesn't have the same focus on multipliers and scores that made Mercenaries so compelling.

Resident Evil: Revelations hooked long-time fans with the promise it would return to the series' survival horror roots, but couldn't resist an attempt at reaching a wider audience. Instead of producing a splintered and botched attempt at blending action and horror, Capcom should have stuck to its guns.