Space Invaders

Created a "Space Invaders" game as per Goal definition. Since I don't consider myself a game designer I want to work from the specification given which is a little bit vague in those "challenge" posts.

Furthermore I added the stretch goals for breakout, adding a little bit of colour into the mix and a savable high score.

Plus the Pong game got some more refinement with added paddle hit derivation and a ball speed increase. Also a bit less good AI. These are not from the specs, but I thought adding those things might be nice.