Funny Kitty Stick simulates cat play time with electromagnetic controllers

The 2023 Game Developers Conference will once again feature Alt.Ctrl.GDC, an exhibition dedicated to games that use alternative control schemes and interactions in new, exciting, and clever ways. Ahead of GDC 2023, Game Developer will be talking to the developers of each of the games that have been selected for the showcase.

Funny Kitty Stick lets players interact with a digital cat, guiding it to endless mischief using a tracking stick and feeling its tugs through electromagnets.

The development team behind this delightful feline simulation spoke with Game Developer about how a silly cat wallpaper led to this game of digital cat play, the thoughts that went into giving the cat agency and a personality in the world, and the importance of making the player feel that connection through the electromagnetic tugging and pawing.

What’s your name, and what was your role on this project?

Wang: My name is Fushan Wang and I am the producer and designer of our game Funny Kitty Stick.

Slawski: I’m Jared Slawski, and I was the engineer on the team in charge of implementing 3D tracking of the cat stick.

How do you describe your innovative controller to someone who’s completely unfamiliar with it?

Wang: Funny Kitty Stick aims to emulate the feeling of playing with a lovable kitten through spatial tracking and haptic feedback. The player can move around with our cat stick controller, properly tracking its current translational position and rotational orientation. When the in-game kitty grabs or paws at the dangling toy on the end of the stick, we trigger an electromagnet that latches onto the real-world toy, providing realistic and surprising haptic feedback. The combination of 3D tracking and haptic feedback dissolves the barrier between the player and the screen, allowing for a stronger connection between the player and their adorable kitty.

What's your background in making games?

Wang: I have dreamed of making games for years. After learning a dozen things during my undergrad, I am now a graduate student at the University of Utah with an Entertainment Arts and Engineering major. Most of the time, I am the designer in the team project, but I also contributed a lot to engineering and music for other indie projects and game jams (like Ludum Dare) in recent years. I created the soundtrack for Funny Kitty Stick as well.

Slawski: I’ve been making games in my free time since around 2013. After spending about 4 years working professionally in the industry, I decided to go back to school to pick up some valuable skills that I hope will help me achieve my dream of opening up my own studio in the future!

What development tools did you use to build Funny Kitty Stick?

Wang: The game is built in Unity, and the hardware integration is implemented via Arduino programming. We have excellent engineers working on both software and hardware development.

Slawski: We’re also using an open-source plugin to directly interface with Wiimote registers, allowing us to access the IR and gyroscope data we need for 3D tracking.

What physical materials did you use to make it?

Wang: The main component of our cat stick controller is a Wiimote that utilizes its IR sensor for spatial tracking. We then house the Wiimote in a shell to make it feel more like a cat toy. The haptic feedback box is also a wooden box containing our electromagnet, Arduino Uno modules, relay module, and other materials.

Slawski: Our haptic feedback box went through several iterations. At one point, we were building a matrix of springs with metal balls attached at the ends, but that didn’t end up conveying the feel that we were going for so we had to scrap all of that hard work.

What inspired the creation of Funny Kitty Stick?

Wang: The idea came from one of my interactive wallpapers in the Wallpaper Engine. It features a cat sitting in the middle of your desktop that stares at your mouse cursor. I thought it would be fantastic if we could make a game that allowed players to interact similarly with kitties, and that’s how the project started.

What thoughts went into turning playing with a cat into a controller?

Wang: From a typical game perspective, it generally feels natural to directly control the avatar in video games. However, we wanted to make something different for our kitties. We didn’t want to directly control the kitty in the room and make it the player’s puppet. Instead, we kept the cat’s energy and focused on the player luring it around as it went about its cat business. This way, our gameplay mainly focuses on having fun with the kitty (via the controller, of course) rather than acting as the kitty itself.

Slawski: If you’ve ever tried to make a cat do something in real life, you already know that it is often a futile endeavor. That’s kind of the feeling that we wanted to capture. The cat kind of just does whatever it wants, and you only have a limited ability to direct it by sufficiently piquing its curiosity. This helps to give the cat a unique personality, making the interaction between player and cat feel a lot more natural.

Why was getting that haptic feedback - the magnetic connection - into the game so important? What do you feel added to the connection between the player and their digital kitty?

Wang: The magnet provides physical feedback for the cat stick. When the kitty grabs or paws at your cat stick, the player can feel the effects of it. That’s the reason we are introducing the magnetic connection into our game. Our hardware engineer put a lot of effort into building the haptic feedback system, which pays off when we feel more than delighted to play with this magnetic equipment.

Slawski: We had a strong belief that having the player experience a pull on the end of the controller via the magnet was going to be a surprising moment, and that surprise was what was going to sell the illusion. Players can think the cat on the screen looks cute and the tracking with the Wiimote is clever, but once they feel that pull on their controller after the cat paws at the toy in-game, that was what we believed was going to make the greatest lasting impression on players.

What design ideas went into creating a game world that would be fun for a person to play with a cat in? What thoughts went into the things the cat could interact with within the game world?

Wang: Building the world (the room) was essential. Since the main gameplay is "interacting with kitties," we wanted to create a casual and lovely environment in which all players could enjoy and feel "at home." Since it is a living place, it naturally makes the interaction between kitties and the room significant.

Slawski: We also snuck in a bunch of surprise interactions throughout the room that trigger specific cat-like behaviors, such as darting underneath the bed or watching cat videos on the laptop! It was important to give the cat avatar some agency, so occasionally it would go off on its own and do things that captured its attention.

Why was it essential that the cat could make a bit of a mess in the world or play with other objects? What do you feel that added to the player experience?

Wang: Kitties are unexpected. The fact that cats can trigger various objects in the room might be annoying in real life, but you can certainly have fun in a virtual world where no property is lost. This makes typical everyday cat mischief fun to discover! The only thing you will care about is how cute the kitty is. Our playtesters also enjoyed this game aspect because the cat can nearly "destroy" all moving things in the room.

Slawski: The biggest thing we wanted to focus on for this game was "player discovery." Although we initially had plans for a narrative and puzzle-solving, we found that the aspect that players enjoyed the most was just interacting with the cat. With that in mind, we tried to lean into that as much as possible by packing the room full of interactable objects. As cats are natural agents of chaos, it seemed obvious to set up scenarios in which the cat causes mayhem throughout the room.

Has building a game around a unique controller taught you anything unexpected about game design?

Wang: Yes. It is a unique experience to create a game with alternative input control. The hardware is constantly being iterated on. On top of that, the research and troubleshooting that went into connecting a Wiimote to a modern game engine was far from easy.

Slawski: It was really interesting having to think about the physical interaction the player would have with the game. Normally, you only have to struggle with getting the player to feel emotions from just pressing buttons on a controller, but having access to a new channel to connect the player to a game was both extremely valuable and extremely difficult, because it required us to think about interactivity in ways we had never considered before.

We hope everyone can enjoy this game as much as we enjoyed making it. Thank you all so much!