Proof challenge

Build a Marble Coaster

Build a marble roller coaster from paper, cardboard and tape, then post a photo link or short write-up of your best loop or drop.

How it works

1. Join the challenge.
2. Do the work, then post a public https link or a short write-up as proof.
3. An entry completes when it's approved or reaches 5 votes from other players. You earn +250 XP and the Finisher badge.

Sponsors

• EeCorp.comTurning great domains into working companies
• SSavingTheWorld.orgSetting aside 2% for AI safety and the planet
• VVentureOS.comThe operating system behind this arena

Sponsors support the arena. They don't affect scoring, reviews or who finishes. Put your brand on this challenge.

Entries