One of the very few occasions where a model 2600 game is "better" than model 800 and newer ones, which isn't saying much because this game is so technologically primitive, it's barely a kilobyte or kilohertz more than Pong. A pizza shop nearby has an original 1978 Arcade coin-op, no one plays and they leave it running 24/7 wasting power and giving its CRT a burn in. But for that classic retro feeling, 2600 Space Invaders is the one. This game single handedly sold 1000s or millions (worldwide) of VCS and many could not have cared less if their VCS did nothing else.
Neat factoid: because Atari knew they had a big hit, and since there's so little happening on screen, they made SI jump straight into "screen saver" (color rotation) mode upon launching and in between sessions, to prevent burn-in on CRT televisions. Imagine if they hadn't.
There is a database of what effects "Frying" has on many 2600 carts, at "2600connection.com" then click Easter Eggs. Now there's debate whether the double shot fire qualifies as an easter egg or a bug, I think neither. It's a cheat or trick. The heart of the matter is actually whether the trick was an accident or done on purpose. Easter Eggs by definition are decoration, not affecting the gameplay nor outcome. SI being a two player game, author must have known the game engine can handle two missiles and two collisions at once, so applying the two shot cannon to the one player mode must've been tempting.
Last, I can't believe how upset some folk get as to whether the SHAPES of the enemy are AUTHENTIC or been changed. Pixel shrapnel is pixel shrapnel.
Holding down Reset (F2) also works in "Stella" emulator (v3.6.1) before launching the ROM instead of "turning on the power", this allows you to double your firing rate. This trick is based on a 2600 model hacking process known as "frying the cartridge" or system.
FRYING meant that one wiggled the power off and on in such quick succession that various cartridges would end up producing eerie tho consistent various effects. One famous example is Pitfall! your character can "go ninja" meaning he turns mostly black and glides thru tree tops. Space Invaders happens to give you double shots if "fried" and holding the Reset while powering on is like a Clean Shortcut for getting double shots. Holding Reset ain't a universal substitute for frying, holding reset rarely does any effect upon a game.
"Stella" emulator includes Fry Emulation, uses the Backspace button to pretend fry the cartridge you have running, and it really works. The downside is someone can accidentally bump into the Backspace key and you're left wondering why your game just became totalled.
Yes, this was a great translation, considering the hardware limitations. I know of a trick that you can use to shoot two bullets instead of the usual one. Before turning on the 2600, hold down the RESET switch while turning it on. Let go of the RESET switch and play the game. When you press and hold down the fire button, you'll find that the base now shoots two bullets, instead of one!! A friend of mine told me about this trick and you can even turn the score over quickly!!
This was one of those early, highly popular arcade games that lent itself splendidly for the 2600. With plenty of difficulty variations (invisible invaders, anyone?), there were plenty of hours of fun to be had here.
This was also a rarity in that it was far superior to the one designed for the Atari 8-bit system. The programmer on that one inexplicably decided to redesign the invaders so they're unrecognizable. You also had them depart from a mothership or whatever that thing is, slowly trotting out in the beginning so you could shoot them right away.
This game alone made the 2600 what it was (is). I remember seeing 2600's FLY of the shelves during that holiday season and this game was the reason why. Plays almost as well as the real thing and the 112 options were incredible at the time. Incredible arcade port and a masterpiece of 2600 programming. Rick Maurer was clearly a genius in that he was able to design this game with NO flicker.