I use the British Council website sometimes in my English classes. There is a wide range of games that are educational. However, today I came across this – http://www.britishcouncil.org/kids-games-magic-monkey.htm.
Try it and then think how to explain to an amazed 14 year old how it works. BECAUSE IT DOES didn’t seem to answer his questions and he seemed not to believe that the computer could read his mind. On the plus side, it did render him speechless.