Apia guides you through API Arcade. Standing in the way: Legacy Larry — every mistake this lane teaches you to avoid. Geolocation, canvas, workers, observers, media — 17 superpowers the browser gives you free.
All 23 lessons below are free, need no signup, and each one opens as a comic issue with a live try-it sandbox, a task list that pays XP, and a narrator that reads it aloud. Progress is stored in your own browser — nothing is uploaded anywhere.