Glad to see someone else be foolish enough to make a multiplayer game for the jam. The Android version keeps freezing when I host a game though. Going up try on PC later though. The coin mechanic looks fun.
For Godot you should look into the webrtc components. They are new in 3.2. Quite a pain in the ass to get to work, because the documentation is a little scattered around but they work without port forwarding and even in the browser. Just need to switch from MultiplayerENet and change how you connect, everything else can stay the same.