I could never get into Thunderbirds as a kid, could never get past those old-fashioned marionette puppets with their weird high-knee walking. But one thing about those Saturday morning repeats did catch my imagination: the hypersonic vehicles International Rescue used, as showcased in the intro.

In Early Access game Stormworks: Build and Rescue I don't have anything as stylish, but my speedboat and helicopter do the job. And there's the possibility of getting more outlandish rescue craft later on—as well as being a game about racing off to save workers who have fallen from an oil rig or towing a broken-down tanker to safety, it's a game about making your own vehicles to perform those rescues with.

You put together an outer structure with simple blocks, then inside that connect together something much more complicated, hooking up your engine to the throttle and the rudders and so on. If the outer shell of each vehicle is made from Lego, the guts of them are Meccano. And even if my own creations are basic, the modders on the Steam Workshop can be relied on to make more interesting things. No Thunderbirds yet, but there is a biplane submarine boat car and a helicarrier.

I spoke to Dan Walters of Sunfire Studios about his game.

PC Gamer: Did you always want to go through Early Access? 

Dan Walters: Yes. There are a lot of great Early Access games that I play and look up to, the greatest was probably Kerbal Space Program. I thought the game fit the format and delivered on its promises wonderfully. We have been enjoying feedback from players for about six months now from the start of our closed alphas.

There is something really rewarding about getting feedback, and seeing people notice even the smallest improvements as you update the game. The flow of ideas and suggestions are also really important, even if we have already thought up and planned the idea that is suggested, it guides what we need to next and what is important with the game.  

We do plan to leave Early Access within a year, but this just a milestone and is more of a marketing thing than declaring the game finished—we already have a post-release road map of features, and we will continue to support the game in the same way, long after Early Access. 

What was the inspiration? Was it Thunderbirds?

I really like when people bring up Thunderbirds, because it shows they get the concept! But no, I hadn't consciously thought of Thunderbirds. The starting point was more of a design concept—I wanted to make a sandbox game, inspired by Kerbal Space Program, but going further—with greater control over mechanics, with internal spaces in vehicles that the player uses and inhabits, and greater player authorship, with a strong narrative in the world with other stuff going on which you can interact with. 

Everything grew from these ideas. The Search and Rescue theme felt right because it generated a lot of logistical puzzles and followed a mission format without being combat-orientated. From here, the game grew, and we have taken inspiration from a lot of sandbox games that we love—Space Engineers, Kerbal Space Program, Human Fall Flat, etc.

The vehicle-building has a kind of Meccano feel to it. Did you play with Meccano as a kid?

I had way too much Lego, and I think some second-hand rusty Meccano turned up at some point. When I was younger, I took apart any electronics that were broken, played with electronic kits, soldered together my own torches or animated things with small motors—nothing impressive, but I was fascinated with how things worked. 

Stormworks takes me back to a lot of different places in my youth: playing with Lego, learning how electronic components work, a friend showing me his Lego Technic excavator with working hydraulics, playing with radio-controlled cars, flying planes and gliders when I was in the air cadets. For me, Stormworks is very personal. It is a magical place of childhood dreams and imagination, and yet a very serious simulation game at the same time.

Our writer Chris Livingston has been playing Stormworks. He wanted me to ask this: "Why do their NPCs stand there in the dark all creepy-like?"

Haha! I suppose this is an incomplete feature, the plan here is for lights to turn on at night and NPCs to acknowledge your presence by turning to face you every so often. As with many parts of our process, we shall make these changes, play the game, watch our players reactions, and think about if there is more required to make the NPCs more life-like.

What are you planning to add, and what have people been requesting? Will vehicles take damage and sink? Will there by traffic to avoid, or animals? 

If it's frequently requested, we are probably planning on working on it soon. Damage is something we will get round to but we are not sure yet exactly how it works. There are already NPC vehicles that cruise around the ocean such as oil tankers, speed boats, tug boats, etc. We are planning on adding air traffic too at some point, all part of making the world feel more alive. 

We also already have about nine species of birds, and a wealth of sea life from marlins to octopi. We have made the art assets for blue whales and great white sharks, but as you can imagine the behavior and interactions are more sophisticated and we haven't got round to adding these yet. 

The plan is to spend a year in Early Access, right? What's the road map looking like?

We have a long list of major updates planned, which are all game-changing additions. After we finish our plans for multiplayer, we are working on the missions modding feature where players can create their own missions and share them on the Workshop. Another update is the advanced editing tools, including sub-assemblies, advanced painting, section planes, etc. After that, it's hardcore mode (which means player death, drowning, fuel system, specialist outfits, etc.) then advanced vehicles (caterpillar tracks, sails, pneumatics, water jets, aero jets), and another four or so major updates on the list. 

The game is still moving forward very fast, mostly because we made our own engine and so we can efficiently add new systems and change the engine as the game requires. No promises, but we are aiming for a major update every six to eight weeks, and the plan on what's next can change depending on what the community ask for. And when we get to the end of this list, I am sure there will be another load of major update ideas.

Finally, how does towing work because I'll be damned if I can get this tanker hooked up to my boat.

You need matching connectors (small connectors), and they both need to be turned on (they emit light when on). If the front connector on the tanker is off, try the connector on the back which is also on a winch. When you do get hooked up, apply throttle gradually!