CallOfAcher and FIFAcher: Vibe Coding Game Variants with My 10-Year-Old Nephew

A week ago, I pasted this prompt by Matt Shumer (150 words, not a single line of technical spec) into Claude Code, and went off to do something else. When I came back: a playable FPS in the browser. Not a demo, not a prototype. A game. I did it again two days later, replacing “Call of Duty” with “FIFA”, and that worked too. Then my 10-year-old nephew took over and grew both games, coming up with…