This is a bare-faced ripoff of Galaxian.  A lot of this sort of shit happened in the early 80's, back before video game companies hired decent lawyers.


Anyway, this will be a different game for you based on whether you care that a video game is fun, or that it's original, because it does improve on Galaxian in some small ways.  The graphics are tweaked a little bit to make the aliens more squirmy, and you can "bend" your shots using the joystick.  The whole shot-bending thing is good fun, 'cause you can fire upwards between two columns of standard aliens and then twitch the joystick at the last second and get the bloke at the top. 

There's also a time limit to each round, which is a perfectly unnecessary addition.

This game deserves to have scorn poured upon it 'cause it's a cocky bastard of a ripoff.  But, the shot-bending thing makes it a little more fun to play than the original Galaxian.  It's a guilty little pleasure, but not one I'll admit to.