Pick a world. Win stars to unlock harder levels, from Grade 3 up through Grade 4.
Erase all stars, badges and report data?
Slide frequency up: crests squeeze together and the pitch climbs. Slide amplitude up: the wave grows taller and gets louder. Turn the volume down before you start.
First-try accuracy on each skill. Second-chance answers don't count. Skills show a rating after 5 questions.