Likewise, it also made a gigantic splash on the home video game market as well, especially since it was the very first arcade port for a home system ever at the time, for the Atari 2600.
Gamers were in for a bit of a surprise with this version, though: there were several cosmetic changes for the game. The arcade version contained 55 invaders; this port had only 36. There were only three different-looking invaders in the original, here there are twice as many. And as far as scoring goes, the arcade "mystery ship" was worth from 50-300 points, while here the purple football-shaped "command ship" is always worth 200 points (except for one variation where it's worth 100, so that's why it's not called a "mystery ship" in this version, obviously).
However, Space Invaders also sold in gigantic numbers, as it had these improvements: a huge amount of game variations -- over a hundred -- whereas with the arcade game all you had was the one game. Plus with the flick of a difficulty switch, you could also have your laser base go from being normal-sized to look at me, I'm The Nutty Professor!
And as far as that simple gameplay went that I mentioned earlier: aliens are invading, and it's up to you to stop them. These aren't the "we come in peace to share amazing technology, help you extend your life by many years, and to give you spam-free e-mail (yeah RIGHT!)" types, they're here to attack. They start as a group near the top of the screen, start marching to the side, and once they reach the edge of the screen, they drop down a notch closer to you; if they get too close and touch the ground, they've invaded, and you lose all of your remaining lives. Of course, you can fight back, but with the more and more invaders you shoot, though, the faster they become. However, the (aforementioned) command ship flies by at the top of the screen from time to time, and if you're lucky enough to hit it, you get a big bonus of 200 points (which the most any invader is worth is only 30 points).
What can I say, the game's simple and addictive, and once you get good at the basic game and it starts to become boring, just try out some of these variations: two players onscreen at the same time is one of the best there is, plus there's invaders that shoot bombs that zigzag down towards you (guess they had too much to drink?), invisible invaders (this actually isn't as hard as it may sound, as the invaders will briefly appear once one is hit), invaders can shoot fast bombs at you, and like I said earlier, you can make your laser base pretty fat by turning the difficulty switch up to A.
Also helping you out with difficulties are bunkers that sit in between you and the invaders, which can withstand a lot of bombardment from the invaders' missiles, although you can shoot nifty little holes through them as well so you can stay protected as you pick off these annoying, unwelcome tourists (this is like being able to look through your peephole at Jehovah's Witnesses and pushing a button so they can be bombarded by rotten fruit via hidden trapdoor). However, one real annoying game variation allows the bunkers to shift back and forth; uck. It's like having a bunch of houses move in front of you when you're trying to aim..."FORE!"
Aiming -- and hitting, in my opinion -- to blow away the original arcade's look succeeds, as the graphics are much better (for once) for the invaders, since there's six different-looking aliens (but they all behave the same, though, like they woke up on the wrong side of the galaxy while having bad hair days, so now they're taking their angst out on us Earthlings), and they all look totally different, one of which has one eye and another one flails his arms and legs around like he's doing jumping jacks; neat!
Even though the sound probably won't seem too neato today, I think it's adequate, and the controls are the best. But then again, how could you screw up move left/move right/fire? Nothing to it, really.
Supreme, supreme, simplistic classic. Nanu nanu, beedybeedybeedy (that's Twiki from the 1980s version of Buck Rogers, in case you don't get that reference), live long and prosper, "mostly harmless" (my foot!), and may the force be with you, and all that.
And blow those S. O. B.s out of the sky!