If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
The Earth is in danger.
Meteorites from space are just before impact.
The only way to stop them is to destroy them.
Our missile base will do that for you, but they need some guidance.
Each meteorite has specific coordinates in form of algebraic problems.
Solve them and destroy them! If we survive the 15 incoming waves of meteorites,
earth will be saved.