Space Invaders for the Atari 2600 was the first ever arcade to home game license, becoming a huge best seller, which it included 112 games with multiple playing variables.
Differences between versions
Even though the basics of the original arcade game remained intact -- invaders would march from one side of the screen to the other, dropping down a notch at each edge, they would fire at the player, there were bunkers for the player's laser cannon to hide under, etc. -- there wer setup, as well as with its many game variations.
This time around, this version had 36 onscreen invaders rather than 55 like on the arcade original. It also had six different kinds of invaders, rather than three, plus they are also worth different point values. There are also only three bunkers on this version (rather than four), but once the invaders started getting close to the Earth (another difference is that this version took place on Earth, rather than on the moon), instead of the invaders erasing them bit by bit as they plowed through the bunkers, the bunkers would just disappear altogether at once.
Also, instead of being a random high point value (except for when the 300 point secret was performed), the Command Alien Ship had only one set point value of 200 points every time it was shot on this version (although in some variations it is only worth 100). No extra laser base is awarded like on the original, and the invaders' and players' shots also do not cancel each other out, as they just pass through each other on this port, plus both the players' and invaders' shots move slower as well. There are also two small color bars at the bottom screen edges indicating the furthest points that players can move their laser cannons to.
Further changes/additions in regards to this cartridge other than playing a "regular" Space Invaders game include the following:
- Moving Shields--shields move back and forth
- Zigzagging Laser Bombs--Invaders' shots zigzag back and forth towards the earth
- Fast Laser Bombs--Invaders' Bombs drop quickly
- Invisible Invaders--Invaders are invisible unless one (or the Command Alien Ship) is shot, which they then briefly reappear
- Large laser cannon--flipping a difficulty switch on the 2600 console to the A position makes players' laser cannons twice as large
Game variations, player setup
Not only are there many variations as far as certain Invaders' characteristics goes, but there are also many variations in regards to player setups as well.
There are two player alternating variations, like with the original arcade game. However, there are also variations to not only have both players onscreen at once, but there are also several competing variations as well, such as ones where if one player gets hit by invader fire, the other player is awarded 200 points. Others include alternating shots where if one player takes too long to fire their laser cannon then it will automatically shoot.
Other variations include ones where one player controls the cannon, along with one player can only move the cannon to the right, while the other player can only move it to the left. Other variations allow one movement and one shot per player, then the other player gets to do the same, and others have one player move the laser cannon while the other player fires.
- Row 1 Invader--5 points
- Row 2 Invader--10 points
- Row 3 Invader--15 points
- Row 4 Invader--20 points
- Row 5 Invader--25 points
- Row 6 Invader--30 points
- Command Alien Ship--200 points, or 100 points in certain game variations
- Other player's laser cannon hit--200 points awarded to other player on certain competitive game variations
Holding down the game reset switch while turning the on the Atari 2600 results in two shots being fired at once during the game.
Modern day hacks
Due to hack-o-matic and the like programs being available nowadays, people can change either the graphics and/or some of the gameplay mechanics to whatever Atari 2600 game they can download the ROM to on emulators.
Most hacks are just graphical hacks, although most have themes to them. For instance, the Vector SI hack mimics the "wireframe" vector graphics from several of the arcade and Vectrex games from the late 1970s through the mid 1980s. Another "theme" (or just a graphics) hack is Kill Dr. Phil, in regards to television psychiatrist Dr. Phil, with several of the top rows of Invaders having a likeliness (somewhat) of him, the bottom few rows spell out the word "HAM", and the bunkers are now television sets.
- Adventure Invaders
- Atari Invaders
- Beast Invaders
- Borg Wars III Invasion
- Face Invaders Deluxe
- Fish Revenge
- Garden Invaders
- Invaders From Space
- Kill Dr. Phil
- NOIZ Invaders
- PC Invaders
- Planet Invaders
- Space Armada
- Space Invaders (Ron Corcoran hack)
- Space Invaders (Franklin Cruz hack)
- Space Invaders Arcade
- Space Invaders Deluxe
- Spice Invaders
- Star Wars Invaders
- Vector SI
The game came with several label variations, which are known as Picture, Text, Red, and Silver labels.
Atari Age Space Invaders page (Complete with links to hacks, pics and reviews of the game)