Starblasters

In “Starblasters” you must defend a sector of space from the invading alien spaceships. Your weapon is a powerful ion beam. But beware! The aliens can fire back. They can blow up your ship or even overrun your sector. Although you have five excellent ships in your fleet, you must be quick, skillful, and sometimes lucky, to hold the aliens off.

  10 REM "STARBLASTERS"
  20 GOSUB 1370
  30 LET TOTAL=0
  40 LET WAVE=1
  50 GOSUB 800
  60 SLOW
  70 GOTO 190
  80 REM [Y][O][U]█[F][I][R][E]
  90 LET CAT=29-C
 100 LET U=C+3
 110 PRINT AT R,U;A$( TO CAT);AT R,U;C$( TO CAT);AT R,U;E$( TO CAT);AT R,U;F$( TO CAT);AT R,U;G$( TO CAT);AT R,U;X$( TO CAT)
 120 IF R=RA THEN GOTO 470
 130 LET FIRE=FIRE+(.4-D/10)
 140 RETURN
 150 REM █[A][L][I][E][N]█[F][I][R][E][S]█
 160 PRINT AT RA,0;J$( TO CA);AT RA,0;H$( TO CA);AT RA,0;J$( TO CA);AT RA,0;H$( TO CA);AT RA,0;I$( TO CA);AT RA,0;X$( TO CA)
 170 IF R=RA THEN GOTO 380
 180 RETURN
 190 REM █[M][O][V][E]█
 200 LET RAX=RA
 210 LET CAX=CA
 220 LET RX=R
 230 LET CX=C
 240 LET C=C+1
 250 LET CA=CA-1
 260 LET RA=RA+(RND<.5 AND RA<18)-(RND>.5 AND RA>2)
 270 PRINT AT RAX,CAX;R$;AT RA,CA;Z$
 280 LET R=R+(INKEY$ ="6" AND R<18)-(INKEY$ ="7" AND R>2)
 290 PRINT AT RX,CX;R$
 300 PRINT AT R,C;Y$
 310 IF RND<(FIRE+DIFF) THEN GOSUB 150
 320 IF C>CA THEN GOTO 590
 330 REM DELAY FOR FIRE
 340 FOR I=1 TO D
 350 NEXT I
 360 IF INKEY$ ="1" THEN GOSUB 80
 370 GOTO 190
 380 REM █[Y][O][U]█[H][I][T]█
 390 PRINT AT R,C;"█[.][.]█";AT R,C;"[.][.][.][.]";AT R,C;"[.]██[.]";AT R,C;"████";AT R-1,C;"[.]██[.]";AT R+1,C;"[.]██[.]";AT R-1,C;"████";AT R+1,C;"████"
 400 LET R=RA-(RA>=10)*INT (RND*D+2)+(RA<10)*INT (RND*D+2)
 410 LET C=0
 420 LET SHIPS=SHIPS-1
 430 PRINT AT 21,3;"SHIPS= ";SHIPS
 440 IF SHIPS<=0 THEN GOTO 1170
 450 LET FIRE=0
 460 GOTO 190
 470 REM █[A][L][I][E][N]█[H][I][T]█
 480 PRINT AT R,CA;"█[.][.]█";AT R,CA;"[.][.][.][.]";AT R,CA;"[.]██[.]";AT R,CA;"████";AT R-1,CA;"[.]██[.]";AT R+1,CA;"[.]██[.]";AT R-1,CA;"████";AT R+1,CA;"████"
 490 LET RA=R-(R>=10)*INT (RND*8)+(R<10)*INT (RND*8)
 500 LET CA=28
 510 LET ALIENS=ALIENS-1
 520 PRINT AT R,C;R$
 530 LET C=0
 540 PRINT AT 21,20;"ALIENS= ";ALIENS;" "
 550 IF ALIENS<=0 THEN GOTO 1270
 560 LET DIFF=DIFF+.3/(D*WAVE*5)
 570 LET FIRE=0
 580 GOTO 190
 590 REM █[O][V][E][R][R][U][N]█
 600 PRINT AT R,C;"█[.][.]█";AT R,C;"[.][.][.][.]";AT R,C;"[.]██[.]";AT R,C;"████";AT R-1,C;"[.]██[.]";AT R+1,C;"[.]██[.]";AT R-1,C;"████";AT R+1,C;"████"
 610 PRINT AT RAX,CAX;R$;AT RA,CA;Z$
 620 IF RND>.5 THEN PRINT AT RA,0;J$( TO CA);AT RA,0;H$( TO CA);AT RA,0;J$( TO CA);AT RA,0;H$( TO CA);AT RA,0;I$( TO CA);AT RA,0;X$( TO CA)
 630 LET RAX=RA
 640 LET CAX=CA
 650 LET CA=CA-1
 660 LET RA=RA+(RA<=9)-(RA>11)
 670 IF CA<=0 THEN GOTO 1170
 680 GOTO 610
 690 REM END OF OVERRUN
 700 REM █[S][E][T]█[P][O][S][I][T][I][O][N][S]█
 710 LET RA=2+2*INT (RND*8)
 720 LET CA=28
 730 PRINT AT 21,20;"ALIENS= ";ALIENS
 740 RETURN
 750 REM █[R][E][S][E][T]█[Y][O][U][R]█[P][O][S][I][T][I][O][N]█
 760 LET R=RA-(RA>=10)*INT (RND*6)+(RA<10)*INT (RND*6)
 770 LET C=1
 780 PRINT AT 21,3;"SHIPS= ";SHIPS
 790 RETURN
 800 REM █[S][E][T][U][P]█
 810 FAST
 820 CLS
 830 PRINT AT 0,0;"████[S]█[T]█[A]█[R]█[B]█[L]█[A]█[S]█[T]█[E]█[R]█[S]█████"
 840 FOR I=1 TO 20
 850 PRINT AT I,0;"████████████████████████████████"
 860 NEXT I
 870 PRINT AT 20,15;CHR$ (128+CODE STR$ D)
 880 REM █[L][O][N][G]█[S][T][R][I][N][G][S]██
 890 LET A$="▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄"
 900 LET C$="[~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~][~~]"
 910 LET E$="[+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+][+]"
 920 LET F$="[=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=][=]"
 930 LET G$="[-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-][-]"
 940 LET H$="[,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,][,,]"
 950 LET I$="[.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.][.]"
 960 LET J$="▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀"
 970 LET X$="████████████████████████████████"
 980 REM █[S][H][O][R][T]█[S][T][R][I][N][G][S]█
 990 LET Y$="[<][0][>]"\n1000 LET Z$="[<][=][>]"\n1010 LET R$="███"\n1020 REM █[I][N][I][T][I][A][L][I][Z][E]█\n1030 LET SHIPS=5\n1040 LET FIRE=0\n1050 LET DIFF=0.1\n1060 LET ALIENS=WAVE*5\n1070 GOSUB 700\n1080 GOSUB 750\n1090 REM █[S][T][A][R][S]█\n1100 RAND \n1110 FOR I=1 TO 10\n1120 PRINT AT 1+INT (RND*19),INT (RND*31);"[*]"\n1130 PRINT AT 1+INT (RND*19),INT (RND*31);"[.]"\n1140 PRINT AT 1+INT (RND*19),INT (RND*31);"[.]"\n1150 NEXT I\n1160 RETURN\n1170 REM █[A][L][I][E][N][S]█[W][I][N]█\n1180 FAST\n1190 LET TOTAL=TOTAL+WAVE*5-ALIENS\n1200 CLS\n1210 PRINT AT 4,3;"YOU FAILED---"\n1220 PRINT AT 8,3;"THE ALIENS GOT THROUGH."\n1230 PRINT AT 12,3;"YOU DESTROYED ";TOTAL;" SHIPS."\n1240 PRINT AT 21,3;"(PUSH TO TRY AGAIN.)"\n1250 PAUSE 10000\n1260 GOTO 30\n1270 REM █[E][A][R][T][H]█[W][I][N][S]█\n1280 FAST\n1290 LET TOTAL=TOTAL+WAVE*5\n1300 CLS\n1310 LET WAVE=WAVE+1\n1320 PRINT AT 8,3;"CONGRATULATIONS---"\n1330 PRINT AT 12,3;"A SUCCESSFUL DEFENSE."\n1340 PRINT AT 21,3;"(BUT WAVE ";WAVE;" IS ON THE WAY.)"\n1350 PAUSE 600\n1360 GOTO 50\n1370 REM █[I][N][S][T][R][U][C][T][I][O][N][S]█\n1380 FAST\n1390 CLS\n1400 PRINT """STARBLASTERS"""\n1410 PRINT \n1420 PRINT \n1430 PRINT \n1440 PRINT "USE KEYS 6 AND 7"\n1450 PRINT "TO STEER EARTHSHIPS."\n1460 PRINT \n1470 PRINT "USE KEY 1"\n1480 PRINT "TO BLAST ALIENS."\n1490 PRINT \n1500 PRINT \n1510 PRINT "DIFFICULTY:"\n1520 PRINT "1 IS HARD"\n1530 PRINT "2 IS MEDIUM"\n1540 PRINT "3 IS EASY"\n1550 PAUSE 10000\n1560 LET D=VAL INKEY$ \n1570 IF D>3 OR D<1 THEN GOTO 1550\n1580 RETURN\n1590 REM █[E][N][D]█

Thank you to Adam Trionfo typing in and testing the program and Ryan Gray for the formatted listing.