This is the second side-entry to the XIII story, and third title of its type, following FFX-2 and FFXIII-2, in the canon Final Fantasy series. It's another experimental addition to the franchise, trying out some new mechanics on familiar territory. It wouldn't be right to call it the conclusion of a Final Fantasy XIII trilogy, but it is the final chapter in this particular story.

The background of that story for any of you coming in fresh would take too much time. Even explaining FFXIII-2, that saw its cast hopping between present and future and forging alternate timelines to save the world, requires more diagrams that you'd have the patience for.

Thankfully you don't need an afternoon on Wiki to get up to speed. Characters may be returning, but with several hundred years passed since FFXIII, it's a whole new world. Besides, the broad RPG strokes are the same: the world's ending, and you and your sword-swinging protagonist are here to save it.

And there's a rather brilliant concept at this game's heart. Let's work through those numbers, starting with the thirteen days. Because that number's the most important.

A fortnight minus twenty-four hours is the length of time left on the globe before a great calamity hits and wipes everything off the map. In Lightning Returns, you'll be aware of that ticking countdown constantly, and be fighting against it. A clock will be ever-present on the UI, ticking down to that final day, minutes in the game world measured in seconds.

Square's built the game's structure to revolve around this time management. There's a day/night system, with NPCs, missions, monsters appearing only at certain times of the day. Clocks are heavily emphasised throughout the world to remind you of time's passing.

It'd be all too easy to shortcut the description to "Majora's Mask meets Dead Rising". But then we'd have to repeat that description because it sounds pretty promising: "Majora's Mask meets Dead Rising."

The reveal, during a presentation in Paris, showed only a handful of areas during a live demo, and gameplay details were light. We don't know what happens come the passing of the thirteenth day, but conjecture presumes a reset back to the first day with all abilities and XP saved. Multiple play-throughs though are expected, as the team explain that you won't see everything first time round.

Time Management systems can be a double-edged sword, typical RPG exploration warring against pressing concerns to be somewhere at the right time, but it's the first time we've seen it as the core of a Final Fantasy game.

We watch the returning Lightning, woken from her crystallisation (newcomers! Think: really long sleep), entering the city of Luxerion via a train system, which will interconnect the four islands that hold the game's locations.

Backtracking is allowed, and you're free to head off to anywhere and start story and mission threads. Here in Luxerion, Lightning's investigating a religious sect - end of the world tends to see such arise - and shadows one group to their hideout. A code punched into a nearby phone booth grants access: Lightning's got to explore the town to find each of the numbers sect members use.

Luxerion continues Square's expanding of XIII's exploration beyond linear pathways. The on-screen map shows multiple open areas, alleys, streets. Store and food vendors wave for attention (Square explain the game will have the greatest number of retailers of any Final Fantasy game). NPCs mill around the streets, and numbers will increase depending on time of day, as the arrival of the latest train spills more of the populace into the area.

NPCs will react to the world events around them as well. There's a sudden flurry of screams and fleeing citizens as creatures invade the central square. A dash towards and sword swipe initialises combat, and as before first strike grants stat and immediate attack bonuses.

Experimentation's bled into combat. Parties are out, as you've the single character of Lightning to worry about during fights, and her you've direct control over. Left stick lets you move her around the battlefield, while you can map specific attacks and magic to face buttons. Coupled with wider environment transversal outside of the battlefield, letting you climb ladders and run around higher platforms, you can see that Square's not nudging but fully pushing the title towards action adventure territory.

The Active Time Battle system's still in place, and the Paradigm Shift system has been tidied and made fashionable. Literally, as this is when the costumes come in.

It's somewhat of a call-back to FFX-2's Dressphere and garment grid. As there, Lightning can cycle through multiple garbs, each with unique stats sown in for a basic set of abilities, and onto which you can stitch unlocked magic, attack and defence options. So you can tailor particular strategies to each outfit, and customise colours for at-a-glance reminders.

You can have three garbs active at any one time, freely selecting between them with the shoulder buttons during battles, and each has a separate ATB bar. In fact the bottom quarter of the screen is wallpapered with those and HP indicators.

We watch a mini-boss battle against a Behemoth that operates as one of the many side-quests (there'll be new creatures as well, the creator confirms), and while it's hard to work out what strategy there could be beyond your immediate move, blocking and dodges become more involving, while the glowing stagger status, opening your enemy to heavier damage, gives you the same rush as a finisher indicator in action games.

The presentation is, to be fair, sparse, and interviews afterwards are equally so - information beyond what's been confirmed during the demo bare bones. Yet there's definitely potential with that the team are doing here, and we struggle to keep speculation at a reasonable level.

A closing video montage shows us some of the areas we'll be visiting during our time in the game, and while the early live demo is maybe starting to show the game's age, these clips look rich in design and scale. Running between huge trees in forests, exploring huts in makeshift villages, loosing yourself in ruins or sliding down sand dunes in an endless desert all suggest a much greater level of interaction and variety with the world. This generation's Final Fantasy no longer looks like a picture-perfect postcard, but a real place that you can touch and explore. That's something we've missed from the franchise for much too long.

With a worldwide release date down as autumn this year, time is short. Therefore it's not going to be long before we start getting a lot more information about the game. Final Fantasy's last few years have humbled the once-great franchise giant, but as a result this feels the perfect time to try something new. We can't say whether this will help reclaim the interest there once was, but it's definitely recaptured our attention.