A shared 3D grid — anyone can leave a block, no account needed.

• One block per cell — placing one is a claim, not a repaint of somebody else’s.
• No account needed: an anonymous block appears instantly in neutral grey and lasts five minutes, while signing in first keeps it under your name for good, in full colour.
• Placements sync live for everyone watching — the grid itself lives on its own site, this page is only the pitch before the handoff.