Changes

The optional speech synthesis, although advanced at the time, adds drama to the gameplay: Although it warns of advancing enemy craft (except for Killer Satellites) and of low fuel levels, both of these features are duplicated by on-screen visual cues and are easily predictable by an experienced player. The sole exception is in the asteroid belts between levels, whose length increases with the level number: The speech synthesizer provides a spoken countdown not duplicated by any on-screen display, such that without the speech synthesizer there is no indication of how long the asteroid belt will last.

===Quotations===