As the world's worst player of video games, I found this one a little frustrating. I wasn't able to escape the rank of "novice", so I didn't actually find out how the game develops. I can tell you how it starts though - an enormously irritating two-tone siren for about five seconds accompanied by the legend "Red Alert, Galactic Attack!". It then settles down into being a fairly predictable game in the "Space Invaders" tradition with good graphics and pretty decent explosion noises (I know - I got zapped a lot!).
I did manage to clear the first screen a couple of times - the second screen is, as you'd expect, faster than the first and features large ships cruising across the top which carry a mystery score if you're clever enough to hit them.
The game comes in two versions - keyboard or joystick control - is written entirely in machine code, and at £7.95 represents good value for money. Galactic Attack - an enjoyable and probably addictive hunk of software, go out and buy it... now!!