
re-test the game with new point structure and speeds.

there's a problem with maintaining difficulty across different screen sizes.

there's the typical aspect ratio and screen size that people will be playing on.

and then there's the arcade cabinet.

perhaps the ship speed should be static and not depend on screen size.

it takes about 3 seconds for the ship to go across the screen, no matter the screen.  (go across the higher of width or height).
