After 20 hours, Final Fantasy XIII granted me permission to decide for myself which three playable characters should be in my party. After 25 hours, Final Fantasy XIII granted me permission to decide for myself how I should develop the characters in my party. After 30 hours, Final Fantasy XIII decided to let go of my hand, but then thought better of it and grabbed hold of it again. Welcome to the evolution of the Japanese role-playing game.

Let's talk about linearity. You've no doubt already heard that FFXIII is linear; the PS3 version's been out in Japan for nearly three months, and importing is a beautiful thing. Well, it's true: FFXIII is linear. So linear, in fact, that for the first ten chapters - approximately 20 hours of gameplay - FFXIII feels more like a dungeon crawler than an epic, expansive JRPG. There are no side-quests to add variety. There are no towns or villages to visit. There is no over world to explore. You move forward, fight, fight, and fight, then sit back and watch a cutscene, then do it all again, pushing ever forward, never deviating from the straight and narrow path upon which you must tread. At the end of a chapter, there's a boss fight, which is usually a pretty horrendous difficulty spike, then, a cutscene, and the next part of the tunnel. The Final Fantasy series, and indeed the JRPG genre, has always been a somewhat linear experience, punctuated by turn-based combat and beautiful CGI cutscenes, and driven by melodramatic narrative. But FFXIII is so linear that it feels like you're adventuring through one long, dark tunnel, and there's no light at the end of it to give you hope that at some point your journey will change course.

It's a deliberate design decision on producer Yoshinori Kitase and co's part, of course - an effort to lend the game what director Momotu Toriyama calls an "FPS style vibe". He's obviously been playing the scripted Modern Warfare series and taken notes. But the team's gone too far in its efforts to evolve the tried and trusted - some say tired - Final Fantasy formula. The result is a sanitised, uninspiring, monotonous trudge through admittedly fabulous-looking surroundings. It's as if you are being driven to the end of the game as you sleep in the back seat.

Other design decisions only serve to exacerbate the feeling that you're never truly in control of what's happening. The game dictates who is on the front line of your party - i.e., who fights in battles - for the first 20 hours of the game. It constantly switches between lead character Lightning (female Cloud), blonde-haired brute Snow, the gun-toting Sazh, Oerba Dia "jailbait" Vanille, the sultry Fang, and the Tidus-a-like Hope, progressing the story from various perspectives until all come together and the game nears its exciting climax. Once you get past the 20 hour point, and you're finally allowed to decide the make-up of your party, it's easy to forget that for huge swathes of the game you haven't been able to. But occasionally, beyond that point, the game reverts to type, dictating your party make-up and defying all logic (the party travel everywhere together, so why can't they all get involved in a scrap?).

You can't even develop your characters the way you want to. Each party member has access to what are called "roles" - classes, really. The theory behind the system is that instead of having characters that only fulfil one role on the battlefield, such as a healer, tank, or damage dealer, each character is flexible. In a fight, at any time you can trigger a "Paradigm Switch", which allows you to change the role of each party member. Say you begin a fight with Relentless Assault, which includes one Commando (melee), and two Ravagers (damage-based spell casting) - that's great for doing loads of damage to your enemies. But when your party's health starts to near zero, you'll want to Paradigm Shift to other roles, making available new abilities. You may want to switch to Consolidation, which includes one Medic (healer) and two Sentinels (tanks), allowing you the breathing space to get everyone up to a safe number of hit points.

As ever, the cutscenes are a joy to behold.

FFXIII dumps traditional levelling-up for a carefully-controlled system via what's called the Crystarium. It's a bit like FFX's Sphere Grid. You spend Crystarium Points - gained from defeating enemies - as you travel around the Crystarium, unlocking statistical bonuses and new abilities, and gaining role levels along the way. This, in theory, is fine. The problem is, the game "caps" the Crystarium relative to each chapter, limiting the number of Crystarium Points you can spend on your party members, and which roles are available to each character. It is only when you beat a chapter end boss, and you get a "Crystarium Expanded!" message, that you're allowed to spend more points in the Crystarium and climb up the role level ladder.

Square Enix's goal in doing this is clear: to negate the need to grind. It's true, for the first ten chapters of the game (about 25 hours), there is absolutely no need to grind, or backtrack (you can't anyway), or move in any direction other than forward. But, ergo, there's no real need to think strategically about what you spend your points on within the Crystarium. You mindlessly evolve your character along a linear skill tree path in much the same way you explore the gameworld, stopping only to occasionally check out what your new abilities do. Admittedly, from the more expansive, open field chapter 11 onwards, all of the roles become available to all of the characters, and you're free to spend as many points in the Crystarium as you like - a good thing, because chapter 11 is much harder than what's gone before, and the dreaded grind rears its ugly head. But by then the damage has already been done.

XIII's 'Stagger' system works like an armour break, allowing you to do extra damage and launch enemies high into the air.

Conversely, however, some mechanics have evolved for the better, and FFXIII's Active Time Battle (ATB) combat system is one of them. FFXIII's combat is like the lovechild of FFXII's divisive Gambit system and FFVII's classic ATB system. Like in FFXII, all three of your front line party members are visible as you explore the game world, and you can avoid many of the enemies you see pottering about waiting to be disturbed. But unlike in FFXII, when combat is triggered there's a short transition to a battle screen, where all the action kicks off.

FFXIII's ATB gauge charges continuously over time. Commands cue up, each one with an associated ATB cost. At the beginning of the game, each character's ATB Gauge only has a couple of segments, limiting the number of commands that can be cued up, but as you progress you gain more - up to a maximum of six. Once the ATB gauge is filled, all the commands play out one after the other in real time. When you've got a three person party going up against multiple enemies using spells, melee attacks, and other abilities, combat is a spectacular, visceral sight.

Now, you may wish to sit down for what's coming next: you only ever control one character during combat. We know, madness, huh? What has Square Enix done? Why have you dumbed down FF for the casual noobs! Calm down, dear. It's actually really good. Yes, you only control one character at once, but, with the Paradigm Shift function, you indirectly control everyone, and the AI is really, really good. Say, for example, you're controlling the gunsword-wielding Lightning, with the broad-shouldered Snow, and the moody Hope backing you up, and with the Strategic Warfare Paradigm (Commando, Sentinel and Synergist) enabled. As Lightning, you'll be concentrating on doing damage to your enemy with melee attacks - dealing physical damage to multiple targets with Blitz, perhaps, or maybe just slashing the crap out of a single target with basic attacks. While you're busy getting your game on, the AI makes sure Snow and Hope are doing their bit as effectively and efficiently as possible: Snow attracting the attacks of enemies with tanking abilities like Challenge, and Hope buffing Lightning and Snow and himself with spells like Shell and Protect.

Of course, the AI doesn't always do exactly what you want it to, but on the whole it's pretty smart. For example, if you use Libra to learn an enemy's weaknesses, your party members will automatically exploit them by using the appropriate elemental attacks. We only ever found the AI wanting when controlling Medics. When a party member is knocked out, an AI controlled Medic always prioritises raising everyone's hit points over reviving the downed character.

FFXIII's combat system is the best the series has seen. It's exciting to watch, fun to use, and, most importantly, brimming with strategy and depth. The only problem with it - and this will be a big problem for some - is the Auto Battle option. Here, with one button press, you can let the computer decide which commands to cue up for you. It does such a good job that it's all too easy to sit back and spam Auto Battle without mentally engaging in combat. The game doesn't do itself any favours by being ridiculously easy for huge chunks of its first 30 hours, only spiking the difficulty for bosses and "Eidolon" fights - FFXIII's disappointing transforming mechanised monsters must first be "tamed" before they can be summoned in battle. It's perfectly possible, then, to play for hours on end by only pushing up on the left analogue stick when exploring and pressing A/X over and over again when in combat.

Vanille reminds us of FFVII's Yuffie. She's chirpy, bouncy, and jail bait.

Story is, of course, massively important for Final Fantasy fans. The great news is that in this regard you won't be disappointed. The game begins with a sabotaged train journey in which members of a resistance force battle against an oppressive government and what's called The Purge - an effort to deport citizens of a spherical world called Cocoon to the underworld below. It's all to do with horrible beings called fal'Cie, which turn ordinary people into slaves called l'Cie. L'Cie are given what's called a Focus - an order, essentially, which they must carry out or face being turned into mindless zombies. Either way, though, l'Cie are screwed. Complete a Focus, and they turn into crystal for the rest of eternity. This is the terrifying fate that Lightning and the rest of FFXIII's eclectic bunch of adventurers face when, early on, they are cursed as l'Cie. The game revolves around their attempt to work out what their Focus is, while unravelling the truth behind the oppressive government Purge.

FFXIII starts slowly - very slowly - but it hits its stride around the 20 hour mark, evolving into an entertaining romp packed full of drama, revelation, and more drama. The six main characters are annoying at first, but they all grow as people as their lives spiral inexorably out of control. Hope, for example, starts off as a spiky-haired whine-bag hell-bent on stabbing Snow in the back for murdering his mother. 'Oh god', you think, 'not another JRPG emo!'. But as you play you can see Hope growing up. In their own ways, all of the central characters do this. It's sophisticated, engaging, and helps drive you to finish the game despite its faults.

And then of course, there are the graphics. FFXIII - the first HD FF game - looks fantastic. The in-game character models are superb. Lightning's hair blows in the wind, Snow's jacket ripples realistically as he dishes out his unique blend of knuckle sandwich, and Sazh's afro... well, it wobbles about like jelly, which isn't realistic at all, but from a distance it looks great. Some of the environments look stunning, too. The Hanging Edge, for example, is what you imagine Midgar would look like had it been created in high definition and powered by current generation processors. The vista in the seaside city of Bodhum is up there with the best Uncharted 2 had to offer. And, Gran Pulse, the setting of FFXIII's infamous chapter 11, is a genuine sight to behold - an open field safari packed with enormous, earth shaking four-legged beasts and rabid monsters sprinting in packs, all overlooked by the ominous vision of Cocoon hanging high in the sky. FFXIII's sci-fi world is as colourful and vibrant as any gamer tired of dour, depressing game worlds could hope for. It is quintessentially Final Fantasy - a distinctly Japanese take on science fiction - fuelled by a wonderfully uplifting score composed by Masashi Hamauzu - that acts as the perfect antidote to the concrete, post-apocalyptic world of Fallout 3 and the lens-flare filled galaxy of Mass Effect 2.

Just check that screenshot out. Wow.

But the CGI cutscenes will no doubt steal the show. They are, quite simply, the best ever; to our eyes as good as the Final Fantasy CGI movies. There are loads of cutscenes in FFXIII, but they are not, in isolation, offensively long, as they are in MGS4. They are bite-sized chunks of animated brilliance, and demand to be watched over and over again. But the more impressive feat is how good the "in between cutscenes" look. These cutscenes - not CGI but not in-game - look fantastic, and sometimes fool you into thinking you're watching CGI. There can be no doubt that FFXIII is a graphical feast worthy of anyone's high definition television.

However, it doesn't always look fantastic. Some of the environments look bland and, dare we say it, lack detail. This is particularly true of the Vile Peaks area - a land built with the debris used by the fal'Cie to construct Cocoon. Almost all of the game's interior sections are boring to look at - a particularly disappointing, and frustrating, sight to endure when you're forced to spend hours soldiering through these locales. It's particularly irksome because you know the game is capable of so much more - you've just seen it in the last chapter.

You all want to know about the differences between the PS3 and the 360 versions, don't you? Of course you do. Well, here's the truth: the PS3 version is the one to get. To our eyes, the gameplay visuals look similar across both platforms, but the cutscenes are vastly different. On PS3, and, therefore on Blu-ray, the cutscenes are displayed natively in 1080p, whereas the cutscenes in the 360 version are sub 720p. The cutscenes in the 360 version look, to the discerning eye, pixelated and blurry. But to the untrained eye, it's a case of much ado about nothing.

Despite the superb battle system, engaging cutscenes, and interesting characters, FFXIII, ultimately, is a disappointment. Taken in isolation, it is a fun game with stunning graphics and a compelling story. But compared with the wider RPG genre, and held up against the lofty expectations of the series' hardcore fans, it falls short. For this reason, newcomers may well enjoy FFXIII more than series' veterans.

You just can't escape the feeling that, in trimming the fat from the series, Square Enix has nicked FFXIII's bone. It's not a bad game by any stretch of the imagination; like a good song, or a slow-burning book, FFXIII grows on you the more you play it. It is, undoubtedly, the best JRPG to come out of Square Enix in a long time. But the inescapable, uncomfortable truth is that it is too linear. Without traditional JRPG features like towns, NPCs, and an over world, there is no real sense of ownership. Upon completing the game, you certainly feel as if you've enjoyed the 50 or so hours you've invested into doing so, but the experience is more throwaway than formative. Despite some incredibly tough monster hunting missions in chapter 11, there's no variation to the game whatsoever.

Characters constantly refer to pushing forward no matter what. For much of the game, that is all the player can do.

FFXIII spends too long easing players into its complex systems - complex systems which, really, aren't that complex. In a recent interview, Kitase said: "It's better to see some people be a little bit bored" than give players too much information to digest. We had no idea he was talking about 25 hours of boredom. Toriyama recently said that lower than expected review scores are the result of press reviewing "from a western point of view", as if to say we're missing the point. But surely, in today's global village and instant communication age, taking a global perspective on a high profile internationally-released video game is the only proper course of action.

As Western role-playing games have evolved, delving into open world, player-driven territory (Elder Scrolls, Fallout) and cinematic, cross-genre experiences (Mass Effect, Borderlands), Japanese role-playing games have remained largely the same - stuck in a rut, even - telling tales of teenage angst and upbeat heroic fantasy we've heard countless times before. We're not saying we wanted Final Fantasy to copy WRPG mechanics. We simply wanted - quite desperately - for Final Fantasy XIII to be the best JRPG of all time. You have to hand it to Square Enix for trying to move things forward - better that than yet another rehash of the tried and tested Final Fantasy formula (the less said about Infinite Undiscovery the better). But it does so along a path so narrow and straight that you long for the days of old. When Vanille is knocked out in battle, she sometimes says: "What went wrong?" It's a question we find ourselves wondering as well.