The last opening

Build 'The last opening' for an invented Sampleton Arcade. Put one moving ball inside twelve concentric rings whose gaps rotate. Use substepped motion and radial collision tests, then let the visitor turn Gate steering to find a route out. Offer Open a passage as an explicit guided route and Launch again for another attempt. Put Gravity, Gap size and Ring rotation in a difficulty disclosure. Show actual escaped rings and collisions, not an invented score. Optional impact tones start off, use the site's audio helpers and stop with the scene. Add Play, Pause, Reset and Keep the escape as PNG. Fit the whole ring system inside the available canvas without cropping, keep native controls and text of at least 12px, allow narrow layouts to scroll, and start still for reduced motion.

1. Advance the ball in bounded substeps. On a radial ring crossing, compare the contact angle with the moving gap before reflecting velocity or recording escape.
2. Keep steering, gravity, gap width and ring rotation in explicit state. Make the guided passage visibly separate from the normal free run and reset its conditions when launching again.
3. Update the escaped and collision counts from actual events. Schedule any impact tone from the collision event only after sound is enabled through the site helper.
4. Contain all twelve rings within the available canvas, expose steering through a labelled keyboard accessible slider, and save the chosen moment as PNG.
5. Freeze the ball and ring motion on Pause or reduced motion. Stop voices when paused and close audio and frame scheduling when leaving the plate.