↑ or Space to burn, ← → to rotate. Touch: hold THRUST, tap to turn. You start drifting toward the pad and have 30 px/s of it for free -- you need roughly 4 seconds of descent to arrive. Land on the pad below 42 px/s down and 26 px/s sideways or you crack it.

Swipe through flying fruit, chain combos and dodge the bombs.

Endless three-lane runner: switch lanes, jump crates and slide under beams.

Thirty seconds of whack-a-mole. Fast hits build a combo multiplier.

Pull back, aim and launch. Topple the three marked blocks in six shots.

Real Newtonian gravity at the real G. Start circular, nudge the planet, and watch the ellipse appear - with live semi-major axis, eccentricity and period.

Nine coupled pendulums on a real g = 9.81. Small-angle period printed underneath; the chaos beside it is the point.

A real Gray-Scott solver. Eight regimes - mitosis, coral, worms, solitons, fingerprint - and the feed/kill map that makes them.

An explicit leapfrog finite-difference solver. Resonance, standing waves and superposition, with the measured period next to the theory.