|Release Date||June, 1996 (v. 1.0)|
December, 2000 (v. 02)
|Mode||Single player only|
Invaders 1978 is a very close approximation of the original Space Invaders arcade game, down to there being no high score save. A brigade of 55 invaders march in formation from one side of the screen to the other horizontally; when they reach a screen edge, they will drop a notch closer to the player's laser base. The invaders drop bombs all the while; if one hits the player's laser base, they will lose a base and the game will end when all laser bases have been exhausted. If the invaders reach the very bottom of the screen, the player will be "invaded" and the game will end no matter how many extra bases the player had in reserve.
Along with firing back at the invaders, there are also four bunkers that the player can hide behind for protection, although the bunkers can be shot through by both the player and the invaders. The invaders will also start erasing the bunkers when they get low enough, erasing the bunkers as they pass through them.
A high scoring U. F. O. also appears overhead several times during a wave.
The only very few minor differences as compared to the arcade original includes either the top invader “winking” or Invaders' explosions not being centered when shot, the number of lives remaining are displayed at the top right, rather than at the bottom of the screen, and the U. F. O. comes out at intervals that are a little longer than with the original.
Also, on the 02 version, the invaders are more aggressive, dropping faster bombs at times, and the U. F. O. will stop coming out when there are nine invaders left during a wave. (In the original arcade version, it would still come out if there were nine, but not if there were any less.)
- Bottom invaders–10 points
- Middle invaders–20 points
- Top invaders–30 points
- U. F. O.–50, 100, 150, or 300 points
- Extra laser base–1000 points
- Start game–any key
- Move laser cannon–left ctrl and alt key (left and right), right ctrl key (right)
- Fire–right shift key
- Exit/quit game–escape key
The 300 point U. F. O. secret from the arcade original is still intact: hit the first U. F. O. on the 23rd shot, then with every 15th shot thereafter will earn the player 300 points every time.