- fixed roll-over bug for energy when you score 10.000 points

- higher speed in the level end sequence and bonus counting

- faster sprite drawing

- FIRE button to start in addition the the START button

- Adapted title screen (flashing, positioning)

- XEX format and a load address of $4000, so it can be loaded from any regular Atari DOS

- a 4 digit energy counter and display

- a fix zero page corruption bug that was present in the original game when placing red saucers on the very bottom of the screen

- support for ESC key to quit the game in addition to the INVERSE key 