A: Yes. If the game uses WebRTC (Peer-to-Peer), you can share the URL. If it uses a central server, you both join the same lobby. Check the repo's README for "multiplayer" tags.
When you combine these two concepts—hosting open-source game code on GitHub and playing instantly via an .io domain—you get a unique digital playground known as . github games.io
const canvas = document.getElementById('gameCanvas'); const ctx = canvas.getContext('2d'); let player = { x: 400, y: 300, radius: 20 }; document.addEventListener('mousemove', (e) => { let rect = canvas.getBoundingClientRect(); let mouseX = e.clientX - rect.left; let mouseY = e.clientY - rect.top; let angle = Math.atan2(mouseY - player.y, mouseX - player.x); player.x += Math.cos(angle) * 5; player.y += Math.sin(angle) * 5; }); A: Yes