Nightfall

    2 LET h=0
    4 IF h=0 THEN GO SUB 1000
    5 LET s=0
   10 PAPER 0: INK 6: BORDER 1
   30 PRINT AT 21,0;"Difficulty (1 to 9) ?": LET d$=INKEY$: IF LEN d$<>1 OR CODE d$<49 OR CODE d$>57 THEN GO TO 30
   32 CLS 
   35 LET d=12-VAL d$
   40 FOR a=0 TO 31
   50 FOR b=d+INT (RND*d) TO 21
   60 PRINT PAPER 0;AT b,a;CHR$ 146
   70 NEXT b
   80 NEXT a
   90 LET u=0
  100 LET p=0
  110 LET f=0
  130 PRINT AT 21,0;CHR$ 20+CHR$ 1+d$+" press any key to bomb"
  140 PRINT AT u,p;: IF PEEK (PEEK 23684+256*PEEK 23685)=255 THEN GO TO 200
  142 PRINT INK 4;CHR$ 144
  144 IF f=0 THEN LET a=u: LET t=p
  148 IF INKEY$<>"" THEN LET f=1
  155 IF f=1 THEN PRINT AT a,t;"": LET a=a+1: IF a=22 THEN GO TO 340
  157 PRINT AT a,t;: IF PEEK (PEEK 23684+256*PEEK 23685)=255 THEN GO TO 300
  158 IF f=1 THEN PRINT INK 2;CHR$ 145: BEEP .01,60-a
  160 LET p=p+1
  170 PRINT AT u,p-1;" "
  180 IF p=32 THEN LET p=0: LET u=u+1: BEEP .1,u
  185 IF u=22 THEN GO TO 1200
  190 GO TO 140
  200 LET x=p*8: LET y=(21-u)*8
  207 PLOT x,y
  210 DRAW INK 6;INT (RND*256)-x,INT (RND*158)-y
  220 BEEP 1,20: BEEP .01,10
  230 NEXT a
  235 GO TO 400
  300 FOR a=a TO 21
  310 IF RND>.99 THEN GO TO 340
  315 BEEP .005,a-20
  320 PRINT AT a,t;" "
  325 LET s=s+1: IF s/250=INT (s/250) THEN POKE 23624,PEEK 23624+8
  330 NEXT a
  340 LET f=0: GO TO 140
  400 IF h<s THEN LET h=s
  410 PRINT AT 0,0;"score: ";s,"hi-score: ";h
  420 GO TO 5
 1000 DATA "a",0,0,96,126,127,8,16,0,"b",0,0,0,32,28,32,0,0,"c",255,153,153,255,255,153,153,255
 1005 FOR f=1 TO 3
 1007 READ a$
 1010 FOR a=0 TO 7
 1020 READ b: POKE USR a$+a,b
 1030 NEXT a
 1045 NEXT f
 1050 RETURN 
 1200 DATA 0,4,7
 1210 FOR a=1 TO 3
 1215 READ c
 1220 FOR b=1 TO 3
 1230 BEEP 1/3,c
 1240 NEXT b
 1250 NEXT a
 1260 BEEP 1,12
 1270 GO TO 32
 1300 SAVE "NIGHTFALL" LINE 32
 1310 STOP