Changes to display include tweaks to the title screen starfield, and the addition of level bonus and game over displays. Controls for thrusting and reversing have been added. Documentation updates to the AUTHORS and README files. Music is played during the game and doesn't stop during the "PRESS A KEY" screen. Internal changes include initialization of the array of floating score images, and the prevention of certain incorrect effects such as UFOs going out of bounds if the planet is destroyed, penguinoids getting caught if you just died, UFOs shooting while they are beaming in, and getting hurt by aliens while they are beaming in.
