Sema — free browser game

Sema is a spin-versus-radius balance game inspired by the whirling dervish ceremony. Hold Space (or Up Arrow, or the on-screen 'Accelerate' button on mobile) to add angular velocity; releasing lets friction slow you down. As you spin faster, the arms swing outward — the arm-tip radius (R) is bound directly to angular velocity, mimicking centrifugal extension. Three concentric note rings appear on the board: an inner blue ring (1 point), a golden middle ring (3 points), and a red outer ring (5 points). To collect a note, the arm tip must be at roughly the note's radius AND sweep through the note's angular position. So fast spinning alone isn't enough — you must spin at the right speed: slow down for inner notes, speed up for outer ones. The arm radius lerps toward the speed target rather than snapping, so begin accelerating or decelerating a few hundred milliseconds before you need the new radius. Notes appear, hold for a few seconds, then fade and silently vanish if missed. A round lasts 60 seconds; the best score is stored locally. Tip: sweeping consecutive notes on the same ring is much more efficient than constantly switching rings — bag the outer 5-pointers in long stretches and only pull in for the short windows when an inner note matters.