Short repair puzzles based on a children's book. Two to five minutes each. Nothing to buy, nothing to sign up for.
Everything runs in your browser. Progress stays on your own device. There is no leaderboard and no comparison with other children.
A note about this domain. This address previously hosted an unrelated set of games for adults, which are still archived at /games/. That older material is not part of the children's site and is not linked from anywhere a child will be reading.
Questions? Write through radimkaufmann.com.