One Line Invaders 2: Mothership's Revenge

In-game screen of Mothership's Revenge.

Program listing on 48K Spectrum

Important note on the above listings
Due to limited space available in the above program listings, the method of keyboard reading is very simple, and does not mask off the 'ear' bit. Therefore the value of 'n' used to compare against the IN command (found at the very end of the program listing) may have to be changed to either 191 or 255 depending on the issue of the ZX spectrum in use, the internal state of a snapshot file, or the emulator and settings in use. Otherwise the keyboard may not respond.

Text Listing

1 DIM i$(3,7):
 FOR g=1 TO 3:
 LET i$(g)=" H H H":
 NEXT g:
 READ m,b,p,a,s,e,n:
 FOR y=0 TO 13:
 FOR x=e TO 26-e STEP 1-e/13:
 FOR i=1 TO 3:
 PRINT AT y-1+2*i,x,'TAB x;i$(i):
 NEXT i:
 LET z=(b>y)*(b<y+7)*(a>x)*(a<x+7):
 LET k=1+z*(b-y-2)/2:
 LET l=1+z*(a-x):
 LET h=i$(k,l)>" ":
 LET q=(b=1)*(m>0)*2>ABS (a-m):
 PRINT AT 0,m;"<=>" AND m,,AT g-1,x+3;"   ";AT g,x+4;"*";AT 21,0;s,,AT b+1,a;" ";AT b,a;"|" AND b-b*h;AT 20,p-1;" W ":
 IF x+3-p+g/20 THEN LET i$(k,l)="":
 LET s=s+h+5*q:
 LET p=p-(IN 64510<n)*(p>1)+(IN 57342<n)*(p<30):
 LET b=(1-h)*(b+19*(IN 32766<n)*(b=0)-(b>0)):
 LET a=a+(p-a)*(b=19):
 LET g=1+g+(g=21)*(y+4-g):
 LET m=(q=0)*(m-(m>0)):
 LET e=x:
 NEXT x:
 LET m=m+29*(e+RND<.5):
 NEXT y:
 DATA 0,0,14,p,0,26,255

Download the game

About the Game

Einar Saukas freed up enough space in the original "One Line Invaders" game to allow for some extra features. Take that as a starting point, add a mothership, apply further optimisations, change the graphics, and we have this sequel "Mothership's Revenge". I orignally added the mothership, but Einar must take credit for doing most of the work on this one. He performed all of the extreme optimisations, to allow the game to fit with in the oneliner compo limit and implemented the new graphics.

The Story

As a commanding officer in the planet wide defence forces, you fought bravely when the chips were down in "One Line Invaders". You succesfully defended the planet from a hostile attack, but little were you to know that the alien menace was about to regroup. This time they'd have the tenacity to attack during broad daylight! They are also getting braver than ever, with their mothership now entering the planetary system for the first time. Have you got what it takes to defeat them a second time? The planet needs YOU more than ever!

Rules of the Game

The keys are t - left, y - right, m - fire
Fire and a direction can be pressed at the same time
You only have one life. If you get shot, the game is over
You can only fire one missile at a time
The space invader's bomb moves sideway along with the invader fleet, so watch out for that!
The invaders will cross the screen 14 times before the game ends
To complete the game, destroy all of the invaders before they land. Also destroy the mothership where possible. Each mothership destroyed is worth an extra 5 points.

Back to Sinclair stuff index