Gbrainy in a brain teaser game introduced in Ubuntu from Lucid Lynx. It is available in karmic repo too. Karmic is current stable version.
The game is mixture of logic, calculation, memory and vebal questions. You can choose to drill on any of of them or all of them. In the end a summary with tips and score is shown.
While in Lucid Lynx the game is available from games menu, in Karmic you have to install it by clicking here .
Here are some screen shots from Gnome Live.