I asked the new @Google Gemini Argon to build a 3D Rollercoaster Tycoon studio + physics simulator from scratch in a single HTML file. You can drag 3D spline nodes to sculpt a 290-ft drop while steel supports rebuild live, then click "Front-Row POV" and ride it at 124 MPH with real G-force physics and a Cyberpunk Night Mode. 1 file. Zero build step.