Solus – Unreal Engine 4 Survival Game Set on an Extraterrestrial Planet | Exclusive Interview

Solus – Unreal Engine 4 Survival Game Set on an Extraterrestrial Planet | Exclusive Interview

February 14, 2014
Exclusive Interviews, Featured, Interview

Space. For some, it is the final frontier. For others, it’s cold and terrifying and very very lonely. For Teotl Studios – the developers behind The Ball and Unmechanical – space is the backdrop for their upcoming survival exploration game Solus. We recently talked with the creator and driving force of Solus, Sjoerd De Jong, at Teotl about life and death a long way from home.

Solus is a first person survival game revolving around the exploration of a lonely, distant planet. With Earth on the brink of destruction, a small team of voyagers is sent to explore the uninhabited planet. After twenty years of space travel, their vessel crash lands on the surface, killing everyone but you. Also lost is the gear you brought with you, leaving you completely alone and unequipped on a distant and uncaring planet, far from home or help.

In order to survive, you must first explore. “Think of it as Robinson Crusoe,” De Jong told us, “but mixed with the underground element of Minecraft and the mystery of the series Lost.” While the planet is apparently uninhabited, that may not have always been the case. “Extensive underground passages and abandoned megalithic buildings are found throughout, and you quickly realize that you are not the first intelligent being who has set foot on this planet.”

During exploration, you’ll come across items that you can use to help you not die. Scavenging and crafting plays an important part in this, finding and combining materials to make useful items. “Many of the things in the world will rely on combining at least two things together, either different items, or an item with a part of the environment.” De Jong said. The example we were given was that of a torch, the crafting of which currently involves a five step process to create a fully functional torch. That’s not to say crafting will be unnecessarily complex, though. According to the developers, crafting will be “a straight forward process” that is based on “figuring out what goes together with what and in what order.” The current system is “mostly based on trial and error”, with the developers deliberately shying away from a hand-holding approach to crafting.


In fact, this entire hands-off approach is reflected in most aspects of the game. Solus is aiming for “a mix between casual and hardcore”, in the hope of emulating a certain amount of realism without the experience becoming too tedious. Currently, this means no permadeath – the developers deeming this “too extreme”. But Solus will be no cakewalk – “we won’t be too overly protective towards the player either… We are really trying to find something in between the two extremes. The game often doesn’t tell you exactly what to do, but at the same time also isn’t too unforgiving when you die.” An example of this is important items. You will be able to toss away important items into irretrievable places with nary a warning message. While you won’t die instantly, you may just become stuck, unable to make your way through a place without the discarded item.

Other game systems reveal this balance between playability and realism. Falling damage will be realistic, but there is no stamina meter, allowing you to “run at the same speed continuously.” Water is required for survival, and fresh drinkable water can currently only be found in fresh water springs in caverns, but the developers are thinking about adding a “decontamination process” to make fresh water from the salty or contaminated water found in other places.

Solus’ game world is not vast. But it is not size that matters here. With the small size of the development team – currently three people working part time – a true open world is “impossible”. Instead, Teotl are relying on a mixture of open areas linked together by linear tunnels. “The world is an archipelago, in which all the islands are connected by a huge underground network of caves and tunnels”, De Jong told us. “Each island can be freely explored, but in order to travel to the next one you will need to make it through those somewhat linear underground sections.” This creates variance between the outdoor sections and the underground sections – both of which have different sets of dangers and advantages. Food, for example, can only be found outside, while fresh water is only found underground. Environmental hazards will affect some areas and not others, “so in order to survive you will need to cope with both of these different kinds of environments, and learn how to best exploit them both.”

Scavenging will be a double-edged sword. While you must find things to survive, Solus is not content to let you sit pretty in one spot. Instead, the need to scavenge will drive the need for exploration – and the need to move on. “You will need to keep moving and work for your survival if you want to make it through.” This means going from the surface to below ground to find the mixture of survival gear that you will be needing. Hunting is out of the question, since the planet itself seems to be completely void of animal life.


Most of the above ground sections are fairly similar in a lot of ways – environmental variance comes from the interplay between above and below, and the differences within the cave systems themselves. Near the surface you will find normal, natural cave structures, “but as you progress deeper underground you will begin to come across caves that are connected to the tide of the ocean above and flood regularly.” Some caverns will be massive, lit by strange crystals. There are even some underground structures similar to those found in The Ball. Eventually, players will reach ice caves. And, if the developers have any time left, they might just throw in a lava layer below the ice caves.

With no combat whatsoever, the sole threat comes from the world itself. Solus’ planet seems to be quite the location for extreme weather events. “Solus has a fully dynamic and random weather and atmosphere system.” De Jong said. “Extreme heat during the day, extremely cold during the nights. Thunderstorms, tornadoes, earthquakes, and meteors can occur at any point and kill you.” The biggest killer will be the temperature. Swings between hot and cold of over 100 degrees celsius (180F) occur between night and day, placing the player in precarious positions. Staying cool during the day and warm at night will be a significant issue if your survival is to be ensured. To this end, Teotl are going to rather extreme computational lengths, going so far as to “calculate the temperature both in the shadows and in direct sunlight, so sticking to the shadows will lead to a cooler environment. We also track the amount of wind and humidity in the atmosphere, which also has an impact on the way you experience the temperature.” The weather will further affect the way the player experiences temperature – cloudy days result in less extreme temperature swings, while rain will soak you and get you colder quicker.

But the world doesn’t need to rely on temperature to kill you. No, there are plenty of other ways to get killed. If you’re silly enough to stay outside during a thunderstorm, you may find yourself getting struck by lightning. Tornadoes will occur during inclement weather. Meteor storms and earthquakes may also cause your demise.

If you think retreating underground will save you from the hostile environment, you’d be partly right. “Underground the climate is stable,” but there are other threats in the caves. Groundwater is prone to rising rapidly, and, in conjunction with the functional tide system, the possibility of getting trapped and drowning is a real possibility. Occasional pockets of toxic hydrogen sulphide gas may also interact… interestingly… with a lit torch, or just plain suffocate you to death. And then there are the regular threats – starvation, getting lost, and darkness – to worry about.


“The underground passages are… pitch black, and are a maze of tunnels. Unless you figure out how to navigate the environment through marking where you’ve been before, as you would in real life, you are likely to get lost and die. Again we won’t protect the players against those kinds of things.”

It isn’t all natural structures, though. Some strange ruins and artefacts hint at the possibility of someone or something else having been there before. Solus’ planet “is not just an uninhabited planet. However there doesn’t seem to be anyone around either.” What is there “bears some resemblance” to Teotl’s previous game The Ball. “Megalithic structures, and references to ancient myths, symbols, and languages. Who really built the pyramids on earth? What if the same thing happened on planets throughout our galaxy?” Surviving among these questions will be at the heart of Solus.

Design-wise, Teotl are attempting to make Solus as immersive as possible. This begins with the UI. Or, rather, the lack thereof. Teotl are trying their damnedest to create a UI-free game. While they do concede they may have to have a few UI messages somewhere – for example a save message – the general aim is to avoid anything that will take players “out of the experience.” This includes the crafting system. Crafting takes place entirely outside of menus. Instead, crafting is implemented directly into the world. The team are also aiming for a complete lack of loading screens to increase immersion, although they freely admit that this may not be a possibility.

And, of course, there is always Oculus Rift support for total immersion. Designing for the Rift is a challenge, with Teotl having to make some significant design choices to accommodate the Rift. Part of the decision to remove as many UI elements as possible was driven by the Rift. Additionally, the in-game character will not have their body viewable in first person to accommodate the Rift. Instead, bodily awareness comes from things like leaving footprints or foggy breath, although Teotl are tossing around the idea to have a non-Oculus option that includes the player’s character model in-game. More specifically, player movement speed has undergone some tweaks to make it feel more suitable for the Oculus Rift. Interestingly, the team are trying to integrate the physical feel of wearing the cumbersome headset into the game by emulating the visual sensation of wearing a helmet in-game through the use of lens effects. The size and proportion of objects in-game have to be carefully considered to make it feel right with the Rift. And level design choices must be made carefully – excessive vertical drops are something that Teotl are avoiding, since “falling can quickly make you dizzy and feel unconnected to what your body feels.” This ties in with the decision to implement realistic fall damage – partly to enhance survival gameplay, and partly to encourage gameplay that prevents physical discomfort while wearing the Oculus Rift.


Luckily, the extensive toolset of the brand new Unreal Engine 4 is helping development significantly. “The big thing for us is the new scripting language Blueprint.” De Jong told us. “It is like Kismet (the Unreal Engine 3 script system) on steroids.” The biggest blessing, however, is how accessible it makes programming to non-programmers. “Blueprint allows me to do so much without ever touching a line of code that it really opens up doors and possibilities.” De Jong admitted. “I would have never been able to do the things I do in Solus without it, so it’s really a game changer for me.” The non-coders at Teotl are finding it empowering, with the toolset allowing them “to take on part of the work programmers used to do.”

Seeming to buck the current indie trend, Solus is currently not planning to be crowdfunded. “Crowdfunding is very popular right now, but developers often forget the flipside of it” De Jong said. “I’ve seen many developers try their luck on Kickstarter and have it backfire badly.” Traditionally, negotiations with publishers or private investors are done privately, and if that funding gets turned down it’s private – “you can always still try your luck elsewhere.” Crowdfunding, however, makes that failure public, “and once you’ve failed in public you will have tremendous difficulties getting any other party still interested in what you are doing, because they will all refer to how the public has rejected the idea.” To De Jong and the team at Teotl, the risk outweighs the potential rewards, as well as the amount of work required.

Solus is a decidedly single player game. “I like single player games as they are right now.” De Jong said. “I have very little interest in various forms of single player blending with multiplayer, or any type of free-to-play mechanics within single player games. And I think there are a lot of people out there who appreciate single player games for what they are today, and for what they have been in the past 20 or so years.” De Jong believes that demand for traditional, offline, microtransaction-free, lump-sum purchase single player games will remain strong. “Just look at how the gaming world responds to the new free to play Dungeon Keeper game for example.” De Jong illustrated. “While there is a lot of hype about free-to-play and whatnot nowadays, I believe there will always be a sizable audience who want single player games that don’t bug you with in-game purchasables, that don’t slow you down to try and extort money out of you, that don’t require you to login or connect to some server just to be able to play on your own for a while, and so on.” In this vein, Solus is not “jumping on the bandwagon” of new social gaming trends – instead, Teotl is creating a “true single player game” with Solus.


Solus’ release is still a long way away – the current goal is a Q2 2015 release date. “We are small,” De Jong acknowledged, “and it is a fairly complex and big game for a team as small as ours, so it is going to take a while.” There will be some gameplay footage released in the future, but it will “probably be about another month or two” before that happens. The Teotl team want to make sure it’s all working properly before footage is released, and, with the game’s planned release still a year and a half away, the team are “not in a rush to show anything.” The only confirmed platform so far is PC, but the team would “love to get it out on next gen consoles as well, but it is something we will figure out later on only”

Many thanks to Sjoerd De Jong and the team at Teotl for taking the time to answer our questions about Solus. We’ll be watching how the game develops, and we’ll definitely be bringing you all the news about the survival game when more information gets released. As always, watch this space.

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