Idle clicker games don’t look like much at first. A few clicks, a number going up. That’s it. But the ones that actually mattered didn’t stay there. They kept stacking layers. Automation kicks in.

Wildly successful: Orteil wrote the code for the game in a single evening. Within just a few hours of posting it on 4chan, Cookie Clicker had managed to attract some 50,000 players. After just one ...