My sketch is for a basic two-player shooter game. Each player one button (to shoot up or down) and one ribbon sensor (to move left or right). Bullets will be coming from the left side of the screen, and the players have to work together to make sure they don’t reach the right side.

The connection aspect comes into play given how players need to communicate. The obvious strategy is for both players to basically function separately, covering different areas to get rid of the red bullets. However, sticking together can actually be the more effective strategy. When two of the player’s bullets collide, it triggers a large explosion which destroys all enemy bullets within a certain radius.
Enemy bullets may also appear at the top or bottom, where they can hit the players. Due to the vertical shooting, players can’t protect themselves, and will have to rely on their partner to have their back.

Finally, the unique physical interaction comes into play in how the players need to move. Rather than just holding down a button, they must slide across the ribbon sensor in order to move. Since this makes the movement of the other player more difficult to predict, it will be a greater test of communication for the players to line themselves up when necessary.
Artist’s Question: The game itself will probably use simple shapes similar to the sketches, but I’m not sure how the physical interface should look. I know each player will have a button and a horizontal ribbon, but beyond that I have no plan. Any ideas?
The physical interface could look like a game controller to mirror the gaming theme!
A pressure input could be interesting to play with mechanically.
Games are a great way to connect with one another, especially with the multiple cooperative elements in this idea. Sounds like fun!
I imagine a three button interface controller or standalone that consists of two arrows (or triangles) in left and right for moving and a bullet button for firing. Will there be friendly fire in this game?
There are arcade buttons for Arduino you could purchase. That might suit the interface very well.
You might find it easier to implement the gameplay in another language than Max.
I like the idea of using arcade buttons. They’re pretty inexpensive and easy to use with an Arduino.