Open the track editor. Pick Load built-in… to start from a course that ships with the game, or New.
Drag control points in the viewport. The strip along the bottom validates the course live — Send to race and Save stay blocked while it reports errors.
Tools → Switchbacks generates a hairpin stack; Auto-bank banks the turns for the speed marbles actually arrive at.
Tools → Reference footage takes a video or screenshot of a real marble run and pins a frame behind the track so you can trace it.
Press T to test-drive it, then ▶ Send to race. It appears in the track dropdown on the race screen.
How a race works
Open the race on a TV, laptop or phone. It shows a code like BRKT and a QR.
In a hurry, or on your own? Watch a race starts one with nobody steering.
Everyone opens join on their phone and types those four letters.
Tap READY. The host taps START. 3 — 2 — 1 — DROP.
Steer across the track. You can't speed up or slow down — only pick your line, and spend your two boosts.
You get a team of four marbles in one colour. Your best one scores; tap switch to take over the leader of your set.
Between heats the host picks New heat to keep the standings, or New game to reset them.
Alpha, and honest about it. Phones join from their own devices — scan the QR on the
race screen, or type the four letters. (A second browser window on the same machine works
too.) It's an early build, so expect rough edges.