interaction designer, creative technologist

U.F.O. Bellies (Game Design, Physical Computing, Alt Controller)



U.F.O. Bellies is a 4-player competitive co-op game, that challenges the players reactions on both physical and psychological levels


U.F.O. BELLIES has been selected to showcase in ALT.CTRL.GDC 2017(Game Developers Conference), you can look at some of the pictures we took in the conference at the bottom of this page.



There are two teams with two players on each side, (4 players in total) and each one of the players wears one giant belly that acts as a game controller. There are three primary color pads on each of the belly.

The game requires the team members to match the color on the bellies with the color of the word on the screen instead of the name of the color.

The goal is that two players have to collaborate and hit the right color of the belly to match the color of the word as soon as possible. There are six different colors: red, yellow, blue and three possible combinations of them- if the color of the word is purple, the two players have to bump red(blue) with blue(red).

U.F.O. Bellies uses the famous Stroop Effect -- if the name of a color is shown in a color that's not matching the name, it takes us longer, and we are more likely to make mistakes than when the color matches the name.

GENRE  Experimental, Physical Game

YEAR  October, 2016

ROLE  Game Designer, Developer(Processing+Arduino)

TEAM  Miyeon Kim (Art, Processing), Xiaomeng Tang (Fabrication, Animation), Xianghan Ma (Fabrication)

CREDIT  Henry J. Lam

Watch our game documentation video below:



Design and Development Process

Game Mechanics Design

Our initial goal for the game is very simple - we want to use the game rule as a “safe environment“ for people to do silly actions without feeling embarrassed, and possibly create some interesting and funny movements along the way. We landed at bumping virtual bellies.

To add a little friction to make bumping bellies hard, we thought of something on the intellectual level, but not too hard. We landed at color matching.

==> First game idea: A color matching game with awkward physical movement - belly bumping.

• The Problem with the first idea: COLOR ==> COLOR. If we already have the color block on the bellies, and just present same color block for color matching, the challenge will be too easy.

• Solution: COLOR ==> WORDS. (We then thought of using words instead of direct color, so it will add one more layer)

==> Second Iteration: Using belly bumping color to match the words, and see who get the higher score.

• The problem remains: the challenge might not be big enough.

• Then the idea of the Stroop Effect struck me, Stroop Effect is a famous cognitive psychology phenomenon, it’s a demonstration of interference in the reaction time of a task.

==> Third Iteration: Using belly to bump colors to match the words(the words themselves have different colors)

Quick prototype and A/B Testing

We made a quick rough prototype using boxes, to

  1. test the A) second and B) third idea, to see if the which challenge level is appropriate.

  2. test if we should use A) time as a constraint or B) how many colors we matched correctly as the constraint.


Our friend also made up some other words like Indigo/Oatmeal on the second color list(third image) to test the constraint.

We eventually decided to go with the third idea and use time as the constraint.

We also did more user testing after this to make decision on progressing the game only when the players match the color right, and the appropriate time to finish the game.


Game Controller Design & Development

When the game mechanics are almost done, I started to figure out how to build the game controller. I encountered a lot of challenges during the design and development stage.

Design Goal 1: In order for players to move around freely, we don’t want the controller to be wired.

Design Goal 2: The bellies have to be durable, so that it doesn’t break easily during bumping

We decided to use fabric to make the belly and Bluetooth to connect our controller to the screen. Use Arduino to collect data, and transmit it to Processing on the computer via Bluetooth.

Challenge 1: How to detect if it’s different color bumps

Challenge 2: Choose the right sensor

I tried to use different kinds of sensors, but none of them works as we wanted. After consulting with Henry Lam - our game design teacher, we find one solution(obvious but very bold):

Use conductive fabric and resistors - without any sensors


I tested out different resistors to calculate the increasing resistance, I wanted to make sure they have enough gap in between so they won’t interfere with each other. I built the Arduino and welded them while my team members built the bellies, developed and designed the graphics in Processing.

Screen Side Design & Development

The problem we encountered with the Bluetooth and Processing was combining two teams results into one screen. In our demo video, we used two computers to show the scores, we can’t compare which team win in that way.

I eventually solved it by using two types of Bluetooth and sending data in different serial ports, designed the split screen and game flow for two teams.



Take a look at our pictures in the ALT.CTRL.GDC 2017 - Game Developers Conference