Pleiades
The cabinet artwork spells the name as Pleiades
but the game has it spelled Pleiads. The name
itself is from Greek mythology, of which there are several
different spellings (Pleiads, Pleiades, Peleiades).
On the second round, shoot all but one alien.
Move the ship to the far left. Wait for the alien to be
in a firing line, and then shoot. Its bullets will now go
through you as long as you keep him in that position. You
can quickly dart left and right, shooting it to death, racking
up points very quickly. After about three minutes of this,
the alien becomes highly annoyed and will hover right below
you, and do all kind of crazy moves!
BUG: When the final alien is killed on the
very first wave, the game says that you will be rewarded
x amount of points, but this bonus is never added to your
score.