Build a multiplayer 3D capture-the-flag browser game with Cursor and Gemini

Try it yourself

What you get

A playable multiplayer browser CTF you can share, built inside Cursor.

Tools

• Cursor
• Gemini 4 Argon (as used by the author)
• A host for the web build (author used Vercel)

Time / cost: Not stated

Steps

1. Scaffold a 3D web game with multiplayer networking.
2. Implement flag grab, tag/bonk and return-to-base win conditions.
3. Playtest locally, then deploy a public URL.
4. Invite others and fix the first wave of bugs.

Copy-ready prompt

Build a browser multiplayer 3D capture-the-flag game with simple cartoon animal characters. Needs: 3v3 teams, grab the flag, tag defenders, return to base to score. Deploy a playable web build. Keep art and controls readable on a laptop keyboard.

Prompt written by AgentPlays, based on @chongdashu’s post. Check the output yourself and approve before anything is sent or bought.

Watch out: Multiplayer netcode is hard; expect iteration. The live demo is the author's build, not ours.

Proof / source

Live demo Author's public X post (Oct 14, 2026) plus live demo at backyard-rascals.vercel.app.