This was one of the first computer games I owned on my Atari.
The game is a little similar to space invaders but this one is in colour and the aliens dive towards you.
Galaxian added an element of drama by having the aliens periodically make kamikaze dives at the player's ship. Scary when yo are playing!
The game's also had a title screen that displayed the message "we are the Galxians - destroy all Aliens".