Fixed some more minor bugs

1.  Changes values in stats to appropriately gauge how long the game
takes.  Also made 5 stars for deaths less than 5 now instead of 1.
2.  Made asteroids slightly smaller for max size in asteroid battle.
3.  Made asteroids in BG spawn later in L2.
4.  Fixed bug where player could repeatedly jump on big spinning
circular rock in L3 slide area.