Zektor

A fixed-screen, overhead shoot ’em up featuring a controllable ship with
thrust and free rotation capabilities, similar to its predecessor Space Fury
(and ultimately to Asteroids/Spacewar!). Your mission: infiltrate and
recapture eight cosmic cities, presently held in thrall by a group of eight
alien robots.

Each of these mechanical antagonists (some male, some female) will taunt you
in its synthesized voice as you approach its captured city. Once there, you
must power through three waves of defense, consisting of drones and fighters –
some enemies may be shielded, requiring multiple laser blasts to take out.
Down the screen travel the indestructible Moboids, which come in three flavors
(one sends ships into an uncontrollable spin, another bounces them away, and
another destroys them on contact); the playfield doesn’t wrap around, and
bumping into the surrounding force-field will kick your ship back.

Once the defenses are repelled, you will arrive at the city itself, where
you’ll face off against its robot conqueror, surrounded by concentric,
rotating shields (a-la Star Castle). The robot will lob energy blasts at you
as it tries to escape; if you manage to sneak a shot through the openings in
its shields, your award is an extra life.