
Mutualism is my final exam project for my Game Design bachelor’s at KADK (The Royal Danish Academy), made in 2019.
It’s a co-op experience utilising unique controllers.
Solo developing Mutualism
My main idea for the project was to create something truly unique I hadn’t seen anywhere before. I used my knowledge of Game Design and technology to achieve this.
The game is a co-op hack-n-slash for 2 players. It uses a combination of traditional controllers and alternative controllers, the latter being the action of physically holding holds with the other player.
You play as 2 colorful blobs who just got married, and together you must protect your wedding cake from being eaten by hordes of hungry enemy blobs. Holding hands will merge your characters into one stronger, but slower, character, better equipped for defeating certain enemies.
All design, art, animation, and programming was made by myself. The music was made by Jonas Gustafson.

Why co-op?
I knew the game needed extensive testing if I wanted to take it serious as a more professional production. If I want to involve more people into my personal games, to playtest and show interest – especially a lot of non-gamers – it always makes a lot more sense to me to make a multiplayer experience. This way, they can use their knowledge and experience from board games, making them more open to playing and interact more naturally with the game.
Co-op, as opposed to competitive, was just a personal choice. I like teamworking experiences and didn’t want to create a game that could feel too competitive, leaving some players annoyed at each other after a game session.
The impact of intimate controllers
The context of it being a university project allowed me to experiment as much as I wanted, so I went all in with focus on using alternative controllers as an element for complimenting social gameplay.
I was hoping the act of holding hands as a gameplay mechanic would add to the social experience …and it it did!
That part, my tutor Alessandro Canossa, was also very interested in, and decided to study the impact of the “intimate controllers”. With certain testing methods, he used the results to write a research paper.

Accomplishments
The project was very successful and resulted in top grades. Alessandro’s paper was submitted to the IEEE Conference on Games (CoG) 2020.
The submission was accepted, and Alessandro presented it it live (during COVID) for the conference.
I also submitted the game to IndieCade 2020. For this, I created a short game trailer, shortly presenting the game and its background. Watch the trailer below.
Designing the controller
I knew I wanted a different type of gameplay, and I knew multiplayer and co-op would be great for engagement of a wider audience for the project’s scale.
This led me to hardware “Makey Makey”, which is a tool that allows anything that can conduct electricity into a mappable input on a computer. The device has been used to create popular videos such as people beating games using bananas as a controller.
I thought about what else could be a fun controller, and this led me to the realisation that humans too, are a great conductor. It required extensive and fast testing though.
The standard setup for Makey Makey is that you connect the device to an object using alligator clips. Well, as it turns out, clipping one of these onto your skin is quite painful for an extended time. However, the input was working!
I then moved on to copper thread, wrapped around the finger, which the clip could easily snap onto, removing the pain. It still worked, but the material worsened the connection.

I studied which materials are the most conductive, and I found that silver is excellent.
I contacted a jeweller friend of mine, and had her make 2 silver rings, with an additional part to them where the clips could snap onto.
Upon testing, they proved to be perfect. The signal worked every single time, as long as the ring was closely fitted to the skin of the person’s finger.
Game Design
Because the unique controls were so important to me, the core game loop came as second priority.
The game design had to be fitted around the controller. This was a fun and useful restriction to work with.
Suddenly having rings as part of the controller led my imagination towards marriage as a theme. Thus the character’s became a newly wedded couple that had to fight off evil to protect their wedding cake.
The game design was inspired by Tower Defense games, and games such as Boxhead, and Vampire Survivors. You must strategise about when to be apart and when to be together in order to survive the longest and to keep your cake (The cake has 3 hit points).
I would have loved to make a full level and more progression, but as most of my time was spend on the technical part, this had to be sacrificed for the scope. Instead it just became a score based game. There is technically an end to the game, but it hasn’t been reached by any team… yet.

Art & animation
As these are my weakest areas, I knew I had to do simple graphics that would look good with little detail. I was much more skilled with 2D than 3D, so 2D it was. Inspired by games such as Castle Crashers, where 2D sprites can walk in 2 dimensions.
The blob character came to mind because I needed a character that could seem like it could naturally fuse with another. That made sense to me due to the liquid nature.
It also made animation much easier for me. I didn’t need to rig anything. I just squeezed the sprite up and down for the walk cycle.
The sword is animated by tweening through different positions.
All animation was done in Unity.
All art was done in ProCreate.

Concept art for character and weapons.

Early sprite sheet animation.
Ended up with a simpler squeeze animation so that I could reuse the same animation for all 3 characters and enemies, and so that it looked more consistent.