Vibe Discovery: I Built a Mobile Game on an Old Phone Without Knowing What I Was Building

The Starting Point “Create a web-based game that leverages the accelerometer creatively.” That was the entire spec. No wireframes, no design doc, no feature list. I typed this into Claude Code running on my Redmi Note 9 - a 4-year-old Android phone with 4GB RAM. Three hours later, I had Inertia - a WebGL marble game with procedural terrain and dynamic camera. The interesting part isn’t the game…