Designing the procedurally-generated space sim Nimbatus
Nimbatus – The Space Drone Constructor (Nimbatus) has players taking to the stars with a supply of self-made drones, using them to explore, mine, and fight through the galaxy. It’s up to the player to decide how they wish to use the planets and systems in front of them, looking at the tasks they wish to accomplish and building a drone to do it. Want an autonomous drone to dig for resources for you? A guided attack drone? It’s up to the player to pick the right parts for the job.
Gamasutra spoke with Philomena Schwab and Micha Stettler of Stray Fawn Studio, developers of Nimbatus, to talk about how they created parts that players could combine to make unique drones for specific tasks, as well as how they designed a universe that would inspire players to get creative with the tools they needed.
Born of creation and destruction
Nimbatus started as a hobby project of our programmer Micha Stettler in 2013. This was the time when Minecraft and Terraria were in full swing and they inspired him to create a prototype of a game featuring fully-destructible terrain. This prototype later evolved into Nimbatus by adding a system to create drones out of many different parts with the goal to play with the destructible landscape.
The game never had a game design document or a detailed plan of all features. We just kept prototyping new gameplay mechanics, keeping the ones that we liked most. We also released a playable demo pretty early, which helped us to flesh out the gameplay, as the community came up with great ideas for new features and gameplay modes.
The joys of destruction and digging
Digging through a planet is a satisfying and almost relaxing experience. It also enhances the sense of exploration, as you can uncover things while digging through the terrain.
On Nimbatus’ inspirations
Nimbatus was influenced by a lot of great games. On one hand, because we are gamers ourselves and constantly get inspired by other games, and on the other hand. because we are friends with game developers and get inspired by discussing our gameplay ideas with them.
Kerbal Space Program has a great approach on how failing is a fun part of the game. You build tons of different rockets and fail miserably, but it’s part of the fun. This is something that evokes creativity in players, and this is why we followed a similar route with Nimbatus.
Analysing games like Besiege or Reassembly, which both have a great creative editor, really helped to come up with a good foundation for the Nimbatus editor.
Arthur Danskin, the developer of Reassembly, also provided us with valuable feedback and insight into his experience of developing Reassembly as an Early Access title. He mostly gave us advice on how to handle feedback and what to expect when releasing a game on Steam Early Access. This was super useful because we have a pretty similar game and share the same target audience.
One piece of advice he gave us was to use a classic online discussion forum to collect feedback instead of relying on Facebook or Twitter. The feedback he received over this forum was much more detailed and valuable as opposed to the feedback he got on social media.
Inspiring creativity in drone-building
We try to keep each part as simple as possible. This makes them easier to understand for beginners, but allows complexity by letting players combine parts in many different ways.
An important aspect while designing a new part is to make sure it can also be used by autonomous drones that were programmed using logic and sensor parts. This way, we give our players the freedom to control drones themselves or program them in a clever way so they can solve missions without any player input.
We don’t really decide what players are able to do with their drones. We just give them the tools to be creative and a goal to achieve. We were really amazed by all the wacky ideas our players come up with to solve the missions.
An earlier prototype allowed the players to choose from multiple default drones as a starting point to build your drone. However, this lead to the problem that the players got less creative and always built drones that play similar to the ones we provided. For this reason, we removed that feature and now force the player to completely build the drones from scratch. This way they don't get influenced or restricted by our pre-designed drones.
Designing new parts for Nimbatus
We start with the idea of how the part should function and implement it by reusing the artwork of a previous similar part. This way, we save time in case we decide to scrap the part again. If the gameplay is fun and we're happy with the part, we start to work on the look and feel.
We design the parts in a way that status information is displayed directly on the part itself instead of showing the information on a HUD or somewhere else. For example, a fuel tank displays its fill level by having a transparent window where players can see the amount of liquid fuel left.
The drone parts can be separated into two big groups. First you need parts to build something that can fly and defend itself such as thrusters, fuel tanks, shields, or weapons. On the other hand, you need sensor and logic parts to be able to automate your drone to make it fully autonomous. This second group contains parts like directional sensors, temperature sensors, distance sensors and logic gates like AND, OR, NOT and many more.
Most of the time the ideas for new parts arise while playing the game and running into challenges or obstacles that you cannot solve with the available set of parts.
Designing missions that inspire drone-building creativity
We have a mission where the player needs to pick up barrels and drop them into a container. For any other game, this would sound like a pretty simple task, but for Nimbatus, it requires you to get creative, because your drone does not have hands to pick up the barrels.
Our players have come up with many different strategies to solve this. They have built drones with arms using motorized hinges to grab the barrel, they used magnets or tractor beam lasers to attract the barrels, or they built multiple small drones to push the barrel around like a football.
On choosing play mechanics that fit well in the world of Nimbatus
The core gameplay mechanic is the building of your drones. When we evaluate a new idea, it's important for us to ensure that the core gameplay benefits from it.
One Idea that we played around with last year was the sumo mode, where we put 2 fully autonomous drones into a ring and the one that gets pushed out first loses the game. This is a perfect fit for our core gameplay, as you really have to be clever and come up with new drone designs to be able to beat other players. The multiplayer aspect also provides a lot of replayability as you fight against thousands of different drones.
On holding off on certain elements during Early Access
Nimbatus has a system in place where we can generate a new galaxy on a button press. However, we have decided to use the same seed for each player during Early Access. This way, everyone sees the same galaxy and the players can help each other if they are stuck. It also helps us to reproduce bugs, because the players can tell us on which planet the problem happened.
We might change this later to allow players to generate a new unique galaxy each time they start a new game.
Learning from Early Access
The Early Access is going great! We have a system in place where players can suggest new drone parts or features and upvote or downvote the suggestions of other players. This allows us to see the most wanted features and parts at a glance.
We have implemented more than 10 parts that were suggested by our players during the alpha testing phase. For example, a factory part that lets you print other parts on the fly. This opened up a whole new possibility space for drones. It allowed players to build space stations that deploy smaller drones and just print them again, in case they get destroyed.
The thing players enjoy most is the creative freedom Nimbatus offers. We don’t have any limits or restrictions when building new drones, and allow players to be fully creative on how they achieve the goals. One of the most demanded features is that we add a campaign mode and a story where you are restricted more and unlock new parts while playing.
This is something we have to keep in mind during development. It will be a challenge to design the game in a way that allows creative freedom, but also lets players experience a story and have a sense of progression.