Here's four games for the younger player that are best of all, free :)
THE GAME OF HATS
The fun part about The Game of Hats is that the players bring hats to the table. Everyone starts with three hats and earn more through play. They place points in their Hats, add use a Hat's powers by adopting its persona. Very simple system using, uh, hats. PDF: Free.
Play a former clown who is now employed as a special kind of police officer. Your beat is the quaint neighborhood of Palookaville (a.k.a. Clown Town), an area almost entirely populated by Clowns, Mimes and other circus performers. Very simple system using boxes of animal crackers, glasses of milk, rubber bands, six-sided dice, clown makeup and clothing, noisemakers, balloons and other fun stuff. Online (HTML): Free.
Play superpowered animals like Wonderdog, Gleek and Krypto- – regular animals with amazing super powers. Very simple system using six-sided dice and a bag of "doggie treats", called Stinky Treats during play. You will be eating these, so you may substitute something else that tastes a little off, like garlic-stuffed olives or plain rye crackers. Online (HTML): Free.
You play yourself and your malicious shadow; a game based on narration – and the urge children have to get themselves in trouble. Your shadow is an invisible person or monster who always wants you to get in trouble. The game always starts with the Players' Characters asleep somewhere; they are all then startled by a sound. What happens after that is up to the Players, and helped along by the GM. Very simple system using six-sided dice and tokens. Online (HTML or PDF): Free.