Treasure Galaxy!

Treasure Galaxy! is an educational computer game intended to teach children mathematical problem solving.
The Master of Mischief has wreaked havoc on Crystal City. To restore it, the player must collect crystals by solving letter code words.
Crystal City is divided into three levels. To advance to the next level, the player has to complete various challenges; the first is related to weighing and measuring, the second to geometric shapes, and the final to calendar dates.
The player can also earn points, called star bucks. They can spend these at a special shop for buying sunbeams to shoot good bright yellow shooting stars. By successfully answering math questions from these stars, the player also earns star bucks.
Disasteroids, evil flying asteroids, serve as the main antagonists.

Source: Wikipedia, "Treasure Galaxy!", available under the CC-BY-SA License.