When we last visited Gory Detail it was way back in 2013 when we exclusively revealed that ex-Rare staffers Chris Seavor and Shawn Pile had begun work on their next project - The Unlikely Legend of Rusty Pup. While the team have issued various developer vlogs in the subsequent years, they've largely kept their heads down and remained relatively quiet - until now, that is. We were invited to Chris Seavor's home in the sleepy Leicestershire countryside not only to partake in a tasty pie and consume lashings of tea (full disclosure here), but to get a look at how Rusty has evolved over the past few years, what the future holds for Nintendo fans and - perhaps most excitingly of all - chat about Gory Detail's next game.

Seavor's home office shows elements of the past he and Pile shared during their time at Rare, arguably one of the UK's most famous game studios. Conker plush toys take pride of place on a sofa, while the a row of N64 titles - Conker and Killer Instinct Gold naturally included - sit on a desk. Elsewhere, posters of cult movies such as David Lynch's Dune and Dragonslayer are almost entirely obscured by Post-It notes with level designs and other ideas scrawled on them - another hallmark of the Rare years, although Seavor points out that it was in fact Shigeru Miyamoto who introduced that particular design approach at the legendary Twycross-based studio.

While three years might seem like a long development period - especially when you're a self-funded indie outfit - Seavor and Pile are adamant that it's exactly how they want it. "Three years is a good cycle for what we're doing," says Seavor. "We haven't stopped in that time - for me, it's ten hours a day, seven days a week and I don't really have a holiday; I sometimes have Sunday off. Hopefully that's evident from the final game."

And from what we've seen, the final game is shaping up to be something very special indeed. The multiple levels of parallax scrolling, superb lighting, particle effects and absolutely exquisite, silky-smooth animation all combine to create a title which looks like it's rendered entirely in 3D, but in fact is a 2D affair which could be seen as the natural evolution of the 'ACM' technique created for Donkey Kong Country on the SNES. Rusty himself boasts some absolutely gorgeous animation, not to mention some brutal death sequences which you'll be seeing a lot of, given the game's intentional 'trial and error' mechanics. Everything has been created with 4K displays in mind too, which means the game is future-proof to a certain extent.

Despite the sumptuous visuals, both Seaver and Pile readily admit that Rusty Pup could end up being a divisive title, mainly down to the fact that it's not instantly obvious what kind of experience awaits the moment you load it up. "We've not made a casual, throwaway game," says Pile. "It's a puzzler and you've got to invest some time in it." This is evident from Rusty Pup's opening levels, which not only serve as an introduction to the game's dark storyline, but also slowly drip feed the various mechanics you'll need to master in order to overcome later challenges.

If we were going to make comparisons, then Rusty Pup reminds us a lot of a cross between the 16-bit classic Lemmings and the more recent Mario Vs. Donkey Kong titles. You have no direct control over Rusty, and instead have to guide him around using lights - he's afraid of the dark, you see, and will move towards the nearest source of illumination. This is the most basic of the mechanics you'll need to learn; later, you have to master laying platforms, powering lifts and using various chutes located around the stage to transport Rusty to his goal.

Along the way you'll acquire cube-like 'brains' which are stored in Rusty's gut before being banked at various toilets dotted around the game - it's only at this point that they enter your inventory, which adds an extra layer of complexity to the simple task of collecting items. These brains are required to open certain doors and obtaining them is likely to be a common challenge for players; a later level features a cloning tool which allows you to create more Rustys - expendable dopplegangers which allow you to collect hard-to-reach brains before being sacrificed. The sheer scope of the game is dizzying, and Seavor and Pile have invested many months of effort into fine-tuning the experience to ensure it flows properly.

"The game is done in terms of all the assets, the game engine and all the core gameplay mechanics, though some of those are still being tweaked," explains Seavor. "Level design is all I do know. I note everything down in what I call my 'Indiana Jones' pad. I go on dog walks and that's when I write ideas down. The process is simple - I know what the level's going to be, I know what mechanics are on it, but I just haven't worked out what the puzzle is, so I'll spend 20 minutes working that out. When I'm sat at my desk looking at the screen, it's difficult and my brain blanks out, so going for a walk and having a pad to jot things down is much better for me."

Seavor admits that designing the perfect difficulty curve for a puzzle game of this type is a considerable task. "I want it to be challenging for the player, but I don't want to put them off," he says. "It's easy to make a game really hard, but it's really hard to pull back and re-tune the difficulty. I find it hard to grade the challenge because I've been playing it so much. The first few levels are the hardest to design - I pretty much scrapped the opening and started over. Scrapping a level that's two or three days of work isn't that big a deal - all the mechanics of the game remain the same, after all - but I'm still doing that now and I'm constantly tweaking things, and once we get it out to people to play, we'll be tweaking things and perhaps even inserting whole levels to bridge gaps in the difficulty. We don't want people to give up after the first level - you want them to get to level six and hit a hard bit but feel they can pass it with a bit of effort. It's hard to design because you create levels in isolation, and then you've got to put it all together and actually play it and make sure it flows."

To make the process of iterating each level easier, Seavor and Pile have created their own level editor which allows them to edit elements and swap out assets on the fly without any coding. "I make thousands of changes each day, and thanks to our editor I can make changes really quickly," Seavor says. "We may even include the editor with the final game so people can make and submit their own puzzles, Super Mario Maker-style."

Back in 2013, the plan was to release Rusty Pup on iOS and Wii U, but in the past three years things have changed ever so slightly. The game will now come to Steam first, with the iPad version possibly coming later. The Wii U edition is still happening, despite Seavor almost scrapping plans earlier this year. "I've changed my mind about the Wii U version recently, for one simple reason - Zelda's gonna be on it," he says. "If Zelda wasn't on it, I'd say forget it. There's no point. Which makes me think that the NX isn't the next step for Nintendo, but that it's 'in step' with the Wii U. Conceptually I'm guessing that NX is probably a hybrid of the iPad and 3DS or Wii U, which would be great for us. We could even end up making use of Wii remote-style pointer control in Rusty Pup, if the rumours are true."

Each platform presents a different challenge from an interface perspective; on PC, the mouse pointer is used to interact with elements and the scroll wheel allows you to zoom in and out, while on iPad, pinch-zoom is used. With the 3DS and Wii U, the lack of multi-touch has forced a rethink, but with physical buttons on offer, these could end up offering more precision. "I like the 3DS the most out of all of them," admits Seavor. "I want to see Rusty Pup on that because it's 3D and it's highly portable, and you have more precision because of the combination of buttons and touch-screen. It's perfect."

As for when you'll be playing Rusty Pup on your Wii U, 3DS or possibly NX, the timeline is less clear. "Because of the way it's written it's not a massive job to port to all these other systems," admits Pile. "It's just a matter of time. I have to juggle the work and I can only work on one at a time." Seavor also explains that the plan is to stagger releases so one can cover the cost of the other. "The Steam release will pay for the next one," he states. "Even so, we don't have huge bills hanging over us so there's no financial pressure. We wouldn't be doing things this way if we were in an office with the backing of a huge publisher, I suppose - it might get done quicker that way and we'd have more people, but even that's a false economy. I get to do exactly what I want, I don't have anyone to say what I can and can't do." Another benefit to working this way is that Rusty Pup's sales projections are quite modest. "We don't need 20 million sales - if we get 20,000 that will make it all worthwhile," says Seavor.

Seavor also reveals to us that he's working on a companion novel for the game, which will expand on its intriguing narrative. "There are three main characters in the game - Rusty, the player and a little girl who serves as an unreliable narrator," he explains. "While there will be little hints of the full story littered throughout the game, the novel will give a more complete picture, but it won't be out until after launch as there are twists I don't want to give away before people have had chance to play the game."

As Rusty Pup's development period winds to a close, it's perhaps unsurprising that Seavor and Pile are already busy conceptualising their next project - one which, according to the pair, will please long-time fans of a certain foul-mouthed squirrel. "We're taking risks with Rusty Pup - the biggest risk is our time," says Seavor. "But with the next game, there's less of a risk. I know exactly who the market is and I know exactly what to do for that market while still creating something interesting and hopefully new. I can't reveal the title yet, but I will say that we might be taking advantage of the Conker name; the term 'spiritual successor' definitely applies here. We're not doing a Conker game as such, but we can take advantage of the legacy." Pile sees an opportunity to plug a gap in the market before someone else does. "We're of the view that if we don't do it, someone else will beat us to it," he adds with a laugh. Both also confirm that the next game will be 2D in nature, rather than 3D.

While a certain group of fellow ex-Rare developers down the road might be stealing headlines with their crowd-funded 3D adventure, Seavor and Pile have been quietly working away on something which - from our brief glimpse - has the potential to be just as interesting and entertaining. Rusty Pup may draw inspiration from the likes of Lemmings - a game which became a global phenomenon back in the early '90s - but it's quite unlike any puzzler we've ever played before; the gorgeous visuals and excellent audio design come together to create a striking atmosphere which effortlessly draws you in, while the tantalising snippets of story maintain your interest as you attempt to unravel the fiendish challenges showcased in each stage. Nintendo fans might have to wait a little longer than others to get their hands on Rusty's debut, but they could end up getting the definitive version thanks to the extensive control options afforded by the Wii U and 3DS. You may have forgotten about this robotic canine, but now is the time to put him back on your watch list.