Uncharted 4: A Thief's End put a full-stop on Nathan Drake's story that wasn't just neat. It was well-measured, beautifully pitched and something of a rarity in any medium: a gratifying end for a much-loved character. It was nothing less than the perfect goodbye.

But now, of course, developer Naughty Dog is back for more.

The Lost Legacy is a bit of an odd one. By the developer's own admission, when it was first announced that Uncharted 4 would be getting single-player DLC it had no idea what shape it would take. Which was fair enough, really, seeing as Naughty Dog had the serious business of finishing off a fairly sizeable video game to get down to.

It was only when Uncharted 4 wrapped last May that work began on the project in earnest, headed up by Shaun Escayg - an award-winning filmmaker who worked on the cinematography and animation for A Thief's End - and Kurt Margenau. It was soon after that it realised the traditional scope of a single-player DLC wasn't enough for what has now blossomed into a standalone adventure. And it's only now, a month ahead of release, that we're getting a chance to play a small slice of The Lost Legacy.

This content is hosted on an external platform, which will only display it if you accept targeting cookies. Please enable cookies to view. Manage cookie settings

If nothing else, you've got to admire Naughty Dog's bravery when it comes to this incoming extension. The Lost Legacy is headed up by Chloe Fraser - the slightly steely Indian-Australian fan favourite voiced brilliantly by Claudia Black - and Nadine Ross, the stern South African mercenary brought to life by Laura Bailey. They're a complex couple, and series fans will doubtless delight in the unlikely pairing, but an hour in their presence suggests the sparks between them are never quite as bright as those between Nathan Drake and company. It suggests that an Uncharted without Drake is going to feel every bit as weird as a Zelda without Link.

Which, it turns out, is part of the thrill for Naughty Dog. "That's what was exciting about it for us," Escayg tells us. "Without Nathan Drake the challenge was how do we ensure it's going to be as awesome if not more awesome than Nathan Drake's story. We're always trying to exceed or surpass our games, to try and make the newest one better than the last one."

"We looked for what the best of all the games were, and compiled them into this - and using the thief narrative of Chloe to enhance the game and change the tone to support that story."

This content is hosted on an external platform, which will only display it if you accept targeting cookies. Please enable cookies to view. Manage cookie settings

That tone can be disconcerting at first - a little overly serious, it lacks the warmth and character that Drake himself brings so brilliantly - but we're only being given a thin sliver of The Lost Legacy to sample, even if it is of the largest play space Naughty Dog has conjured to date. If this is something of a greatest hits package for Uncharted, then this most definitely is its homage to the expanses of A Thief's End's Madagascar level, only served with a small twist.

That twist being that this is a fully non-linear level, an open-ended space you're free to explore at will. It's a small masterclass in design, the outrageously beautiful backdrop of India's Western Ghats kept in order by sight lines that are expertly crafted, always guiding your eye towards an objective that would otherwise be lost in the vastness. There are plenty of objectives, too - whether that's the three towers you're asked to visit as your primary tasks, or one of any number of diversions along the way. This, it turns out, is an Uncharted with optional puzzles and weapon crates that can be prised open with the new lock-picking mechanic. You certainly can't say it's just more of the same.

It is familiar, though. There's a slight fussiness to Naughty Dog's approach to puzzles that doesn't sit too well with the promise of freedom - there are times when you wish as much imagination and creativity was on spent the puzzles as has been expended elsewhere, but such has always been the way with this series - and a little too often it feels like pixel-hunting rather than a more satisfying breed of problem solving. Likewise, there's a clunkiness to the action that doesn't necessarily fit the stealth that's encouraged as you take out enemy camps, but such quirks will hardly be a surprise to series veterans.

Uncharted 4's entire multiplayer package is also being included with The Lost Legacy, which is a generous gesture.

The exploration is made possible, once again, by a glorious 4x4 in what's still the best off-road driving this side of Spintires. There's a lovely schlep as it works its way through mud, and a real joy in finding points of traction as you tread on uphill. I'd actually take an entire Uncharted spin-off based on the jeep itself - it's got just as much personality as any other character in the series - and maybe one day I'll get my wish. It's interesting to see how Naughty Dog's stance on the future of the series has softened since the launch of Uncharted 4 last year, and how it seems more open to explore other side-stories in its universe. "I can't speak for the studio and I don't know what we'll be doing next," Escayg says, " - it's a very large world to draw off of, there's a lot of cool characters that could be explored, that should be explored." Further spin-offs sound perfectly possible, but I wonder whether it'd be Naughty Dog itself who'd be responsible for them.

The Lost Legacy, meanwhile, looks like a curious outing that's yet to show its true self - and you can't blame Naughty Dog for wanting to keep the pleasures of its expert storytelling preserved for everyone to enjoy when it comes out late next month. After the superb send-off offered by A Thief's End, it runs the risk of being a slightly awkward return - a little like that uncomfortable moment when you make an emotional farewell at a station only to realise seconds later that you've ended up on the same train. But, then again, maybe this one isn't goodbye after all.