Alien
The Alien ship passes overhead, razing the ground below with its power beam, and dropping swarms of deadly Veepods. Moving swiftly across your territory you fire your missiles as long as the power holds out. When a recharge is necessary, your base changes shape, and you must ride out the dangers undefended. As an added difficulty, you can choose to have an invisible Alien, indentifiable only when it fires, and providing minimal guidance for your missile positioning.
1 REM ALIEN.
2 REM PAUL STANLEY.
3 MODE 1:BORDER 0:INK 0,0:INK 1,24:INK 2 ,20:INK 3,6
4 HS=0
12 GOSUB 1000
15 GOSUB 2000
17 WINDOW #0,5,36,1,25
18 PAPER #0,0:PEN #0,1
19 CLS #0:FOR X=1 TO 300:NEXT
20 X=0:Y=1:Z=14:5=0:C=0
25 PEN 3:LOCATE 17,1:PRINT"HI—SCORE:";HS 30 GOSUB 71
35 IF RND>0.97 THEN GOSUB 200
40 IF RND<0.08 THEN GOSUB 78
60 IF C=3 THEN GOTO 305
61 Z=Z-2*(INKEY (1)=0 AND Z<26)+2*(INKEY (e)----o AND Z>0)
62 PEN 3: LOCATE Z+1,22:PRINT " ";CHRS( 233);" ":PEN 1
63 IF INKEY(9)=0 THEN GOSUB 100
68 PEN 2:LOCATE 3,1:PRINT"SCORE";S:PEN 1
70 GOTO 30
71 X=X+1:LOCATE X+1,Y+1:PRINT" ";G$
72 IF X=29 THEN LOCATE X+1,Y+1:PRINT" ":X=0:Y=Y+1
73 IF Y=21 THEN Y=1:C=C+1
74 IF C=3 THEN 305
75 RETURN