This wonderful game has many educative activities for children aged 2 to 10 years old and not so. I also used to exercise my brain in some quests, :) Oh, yeah, there are some interesting computer discovery tasks, algebra solving problems, science, geography, various small brainfuck games, learning's etc.
I remember, it was 2008 or before I found this game, and I was impressed from how many languages this game supports: English, French, Portuguese etc. Now, i can see the game is also available for Windows and Mac OSX users too. See here for all available options.
Archbang & Archlinux users can install it the usual way:
sudo pacman -Sy gcompris gcompris-data
Do not play it too much, give a turn to your nephew, or little brother, heh :)