Space Invaders 1.0 Defeat waves of MEMES with the laser cannon earning as many points as possible. Use LEFT and RIGHT ARROW keys to control the laser cannon. Use SPACE BAR to fire at descending aliens. Try to destroy the aliens advancing towards the bottom of the screen. As more aliens are defeated, the game's speed will increase. Defeating the aliens brings another wave that is more difficult. The aliens will attempt to destroy the cannon by firing at it while they approach the bottom of the screen. If they reach the bottom, the alien invasion is successful and the game ends. A special 'mystery ship' will occasionally move across the top of the screen and award bonus points if destroyed. The laser cannon is partially protected by several stationary defense bunkers that are gradually destroyed by blasts from the aliens or player. -Space Invaders (Wikipedia 2015) http://scratch.mit.edu/users/codergeek/
