I created a game for a LD Jam 2 years ago (NodeJS backend with socket.io HTML5/Canvas). You could play in the browser against other people. I just realized I am still paying for the Amazon instance and the page actually still loads and the chat still works as well as the zoom in and out feature but I cannot control the ship. Also I have not done the Lets Encrypt process so my SSL cert is expired.

Anyways, continuing the theme of making it have multiplayer support, I will be creating my submission this year with LibGDX, Box2D and Kryonet. I will probably only make ports for Desktops, but maybe I will try to make an HTML version and host a server again.

The big difference is that I want people to be able to host the server themselves and play alone or join other people's servers (kind of like the Minecraft model).

Some of the themes I think will work quite well for this. Let's see if I can defeat the sleep monsters and get something playable completed.

Edit: I just spent a few hours remembering how to get Let's Encrypt working: https://worldy.io/