The player controls a spaceship that shoots at aliens descending from space. How to play the game: - Click the green flag to set things up. - Use arrow keys to move the spaceship. - Use SPACE to shoot bullets at aliens. - Aliens shoot missiles at random. If hit, the spaceship first loses shield strength and then lives. - At each level, aliens descend faster and shoot faster. - You win if all invaders are destroyed before they can land. - You lose if you lose all lives or if an invader lands.
If you would like to understand how this program was designed, look up this PDF: http://www.abhayjoshi.net/spark/scratch/blog/space-invaders.pdf
