Space Invaders

This is the old Game Spaceinvaders ;)
I have tried to program it like i would like to play it.
There are still many Bugs I have to attend to, but I will try to fix them as soon as possible.
Graphics & Sounds are still missing.
Contols:
move with "a"&"s"
shoot with space
Bugs:
-When the Aliens get to low, there's an Error
-Sometimes the Keyboard input doesn't seem to work

Yet to do:
- more Aliens, let them move blockwise
-implement Sounds and Graphics
-Clean up code
-comment code for documentation
-implement more features ;)