Can we make a multiplayer game without a remote server?

Hello,

I started to use socket.io, express and phaser to make multiplayer games.

I followed this tutorial: https://phaser.io/news/2017/03/socketio-multiplayer-tutorial

and I used Heroku to host and serve my game.

However, I was thinking that, in the case I want to make a coop game, I would not need the server to be always running on Heroku.

Instead, I could use one of the client machine as the server? Do you think that this is possible?

Thanks,

Nodregam