Rust+Box2D Browser Physics Sandbox with Multiplayer

I've made a browser videogame (physics simulator). The idea is that you draw machines and you destroy targets with them. It's still a prototype-level project, but I've put a lot of time into it, and it has both single-player and multi-player. I'd be happy to hear if it's interesting and any ideas about developing it further.

Link (click on its lower-right for full-screen): https://v-yanakiev.itch.io/machina

Here are a few videos with machines:

Helicopter bomb: https://www.youtube.com/watch?v=vqSt4tpoKww

Torpedo: https://www.youtube.com/watch?v=XrR5jtleDTk

Vehicle bomb: https://www.youtube.com/watch?v=cBANeAxWhBQ