With apologies for bursting some of the bubble of euphoria that's surrounding many reviews for Metal Gear Solid 4 right now, this latest game in the franchise is a frustrating mixture of flat-out brilliance combined with too many of the indulgences that have hampered the series to date. That won't be offputting to long-term fans of the series, but there's plenty to keep casual gamers at bay.

The key crime is the insistence on lengthy cut-scenes that, for much of the time, leave you feeling like you're part of a game that you're simply not allowed to play. Now we should be clear: the production values of these cut-scenes are quite extraordinary, with visuals that will be running in the windows of Currys for a good few months to come.

But once the impressive sheen has fallen off, it's like watching a film that you didn't want to rent. Sooner or later you end up skipping them (unless you're a keen follower of the narrative that's run throughout the franchise), otherwise you're left out of the action for minutes at a time.

That's a pity, too. Once you get past the jabbering talking heads, there's a good, wry script underpinning the game, and one that's willing to pull its fair share of narrative surprises. But in what is Snake's final adventure (and the central character has aged a lot, a bold move in itself for such a game), it's a shame that the Metal Gear Solid franchise hasn't got over its indulgences.

Fortunately, when you are allowed near the game, you appreciate just what the hype is all about. The original Metal Gear Solid (and arguably still the best) all but single-handedly invented the sneak and stealth genre of games, but there's a lot more to the series than that.

This latest adventure experiments with several gaming conventions, and while sneaking around does still tend to be the most successful of them, there's a tighter combat system too, and some fabulous weapons to play with. What's more, it's a living, breathing warzone at times, and that makes the game feel like there's a lot more going on around you.

The stealth is aided by the OctoCamo suit, which - when you lie still or crouch against a wall without moving - blends into the surroundings, and significantly limits the ability of enemies and sensors to see you. If you pick one of the tougher difficulty levels, it proves to be far from foolproof, but a bit of practice makes this as devastating a weapon as any rocket launcher.

Furthermore, this single device manages to ratchet tension to quite extraordinary levels at times, when someone you're trying to avoid comes within sniffing distance, without being able to see you.

Particularly in the first half of the game, the sheer ambition, scale and audacity of Metal Gear Solid 4 leaves you willing to forgive almost everything about it. The further you get in, though, the more diluted the game becomes, with the indulgence of the cut-scenes going into some kind of overdrive. That said, those who have closely followed the franchise will surely get a kick out of the resolutions that the game brings, and the familiar faces that pop up, even if it does all get really quite confusing.

At its finest, Metal Gear Solid 4 is comfortably the most exciting, downright astounding game on the Playstation 3 to date, and a multimedia tour de force, too. It's hard to remember the last game that was this engrossing, this tense, and had so many moments where you simply wanted to stand up and clap in appreciation (it even plies you with little jokes and moments that can't help but bring a grin to the face).

But this comes at a cost, for the ambition with the gaming elements has been matched by the continuing need to turn it all into a protracted film, and that remains Achilles heel of the series. Overlook that, or sacrifice it all by some liberal skipping, and you don't get the full experience the game has to offer. It's a no-win trade off, in that sense.

In spite of the problems, though, there's really nothing else that can match Metal Gear Solid 4, and it demands to at least be checked out. By turns stunning and frustrating, emotions often separated by a single minute, it's an extraordinary piece of work. And sometimes an extraordinary game, too.

A brilliant game, with some ambitious but often relentless cut-scenes. It's a PS3 killer-app alright, but for all its qualities, it's a little way off perfect.