Space Invaders

To understand how much this little game invades our popular cultures you need to check this link (I will not apologize for bad puns)
Space Invaders Image Search
It permeates everything from chairs and wall decals to watches, rings and packing tape. Japan really did invade the US but not with a military. If Pac-man didn't, this game proves they were able to influence our culture and take our money doing it.
Space Invaders was released in June of 1978. Midway licensed it and brought it the US. It was an instant hit. By 1982 it has grossed $2 billion. It was also the main cause of the 100-yen coin shortage in Japan after its release.

In Space Invaders, you control a single mobile laser cannon. You can move it horizontally across the bottom of the screen with a 2-way joystick. You also have a button to fire your lasers at the 55 aliens trying to stomp out our planet's existence. There is also a bonus UFO that will appear above the aliens that can be shot. You also have 4 bunkers in which to hide from enemy fire. But those can be destroyed and if the aliens get to low, the bunkers disappear all together. The game is played over a background to give it more of a Space Invasion feel.
One of the most intimidating things about game play was actually discovered by accident. In 1978, hardware was so limited that the creator of the game,Tomohiro Nishikado, had to design the hardware to make it work. This led to the processor being over taxed. So as you shoot the aliens and they disappear, there is less for the processor to draw and move so the game and music speed up. When Nishikado found this, he incorporated it rather than try to create a fix for it.
The current high score of 184,870 is held by Richie Knucklez and was set on November 5th 2011.
This week's challenge is to achieve 1500 points.
You can find the game here
