Gravityflip Katana Runner Game Builder

Run a five-lane neon megacity and flip gravity onto the ceiling track in one tap. Claude Code builds a 3D Three.js endless runner in one HTML file: katana slashes, double jumps, slides, grind rails, drones, laser gates, a black-hole shader horizon, bloom, three colour sectors, a combo meter, synth music and an invincible ?showcase=1 trailer. Needs internet: Three.js and gsap load from a CDN. 5 variables re-skin it.