|Space Invaders (P. J. Crossley)|
|Developer||P. J. Crossley|
|Mode||Single player only|
The basic game of Space Invaders by P. J. Crossley does not differ much from the arcade original. However, three slightly different play options are also available.
The basic gameplay of this version of Space Invaders pretty closely follows the original, with the invaders moving from one side of the screen to the other in a formation, dropping bombs all the while. Once they reach a screen edge, the formation will drop down a notch closer to the player’s laser base. The player can hide behind bunkers for protection from invader fire, as getting hit by an invader missile will destroy the player’s laser base and the game will end when there are no more remaining bases. A high-scoring U. F. O. will also appear above the invaders several times during a wave.
This version has several minor differences from the original, as there is no animation sequence for when the player loses a laser base. Their laser base will also start off in the middle of the screen, rather than from the left. Their shots are also slightly slower and the U. F. O.s move slightly faster than on the original game. Enemy fire is also not restricted to the lowest invader in a formation, as their fire can come from an invader in an above row, which passes through other invaders. The invaders also will not move at a high rate of speed when only a few are left, plus they will not erase bunkers when they come into contact with them, they will only pass through them.
There are also only three large bunkers, rather than four like on the original. The score value of a U. F. O. is not revealed when it is destroyed, unlike with most versions in general, and the player’s score is also not shown until the end of a game. The U. F. O.s also appear at irregular intervals, even when very few invaders are left (as the U. F. O.s would quit appearing if there were less than nine remaining invaders on the original).
Four different “wave types” can be selected at the main menu.
The first wave type is the regular Space Invaders game. In the second type, the vertical rows of invaders bob up and down alternately (i. e. one vertical column of invaders will move up while the rows on the other sides of it will move down). In the third wave type, the formation moves up and down in a wave-like manner, and in the last type, the invader formation moves up and down as one unit, unlike in a rippling wave-like manner like with the third one.
- Move laser cannon–left/right arrow keys
- Exit game–escape key
- Display game information–F1 key
- Full-screen/window version toggle–F4
- Choose wave type–1-4 number keys
- Exit program–escape key
- Bottom two invaders–10 points
- Middle two invaders–20 points
- Top row invaders–40 points
- U. F. O.–random
- The screens show the game in progress, as well as a clone of the bezel artwork found in the arcade original.
- When the player shoots through a bunker, this usually causes holes to appear from the top of the bunker that then move downward. It is unknown if this was intentional or a bug.
- Unlike with the original game that did not have a high score save, not only is there space for 10 scores, but the player can also input their name (or multiple words), rather than just three initials.