Wave Clear and Progression
All enemies destroyed triggers a wave clear message, bonus points, and the next wave loads from DATA.
When every enemy in a wave is destroyed, the wave is clear. The game pauses briefly to celebrate: “WAVE CLEAR!” appears on screen, bonus points are awarded, a fanfare plays. Then the next wave loads from DATA and the fight continues. This unit connects the five waves into a continuous progression.
The Program
5 REM === WAVE CLEAR AND PROGRESSION ===
10 BORDER 0: PAPER 0: INK 7: CLS
15 GO SUB 800
20 LET sc = 0: LET hi = 0: LET li = 3
22 LET wv = 1: LET tw = 5
25 DIM e(20): DIM r(20): DIM t(20): DIM h(20)
27 DIM b(1): DIM c(1): DIM d(1)
28 DIM m(3): DIM n(3): DIM o(3)
40 REM === load wave ===
42 RESTORE 900
44 FOR i = 1 TO wv - 1
46 READ ne, nr, sp
48 FOR j = 1 TO ne: READ a, a, a, a: NEXT j
50 NEXT i
52 READ ne, nr, sp
54 FOR i = 1 TO ne
56 READ e(i), r(i), t(i), h(i)
58 NEXT i
60 LET fx = 10: LET fy = 2: LET fd = 1
62 LET px = 15: LET py = 20
64 LET tk = 0
66 LET d(1) = 0
68 FOR i = 1 TO 3: LET o(i) = 0: NEXT i
70 CLS
72 GO SUB 600
75 GO SUB 500
80 REM === game loop ===
85 LET k$ = INKEY$
90 IF k$ = "o" OR k$ = "O" THEN GO SUB 300
95 IF k$ = "p" OR k$ = "P" THEN GO SUB 310
100 IF k$ = " " THEN GO SUB 320
105 GO SUB 350
110 LET tk = tk + 1
115 IF tk >= sp THEN GO SUB 400: LET tk = 0
120 GO SUB 450
130 GO SUB 600
135 GO SUB 650
140 GO TO 80
300 REM === move left ===
302 IF px <= 1 THEN RETURN
304 PRINT AT py, px; " "
306 LET px = px - 1
308 PRINT AT py, px; INK 7; CHR$ 152
309 RETURN
310 REM === move right ===
312 IF px >= 30 THEN RETURN
314 PRINT AT py, px; " "
316 LET px = px + 1
318 PRINT AT py, px; INK 7; CHR$ 152
319 RETURN
320 REM === fire ===
322 IF d(1) = 1 THEN RETURN
324 LET b(1) = px: LET c(1) = py - 1: LET d(1) = 1
326 PRINT AT c(1), b(1); INK 7; CHR$ 148
328 BEEP 0.01, 20
329 RETURN
350 REM === move bullets ===
352 IF d(1) = 0 THEN RETURN
354 PRINT AT c(1), b(1); " "
356 LET c(1) = c(1) - 1
358 IF c(1) < 1 THEN LET d(1) = 0: RETURN
360 LET ht = 0
364 FOR j = 1 TO ne
366 IF h(j) <= 0 THEN GO TO 380
368 LET sx = fx + e(j): LET sy = fy + r(j)
370 IF b(1) = sx AND c(1) = sy THEN LET ht = j: GO TO 382
380 NEXT j
382 IF ht = 0 THEN PRINT AT c(1), b(1); INK 7; CHR$ 148: RETURN
384 LET d(1) = 0
386 LET h(ht) = h(ht) - 1
388 IF h(ht) <= 0 THEN GO SUB 510: RETURN
390 PRINT AT fy + r(ht), fx + e(ht); INK 7; CHR$ (143 + t(ht)): BEEP 0.01, 10
394 PAUSE 2: PRINT AT fy + r(ht), fx + e(ht); INK 6; CHR$ (143 + t(ht))
396 RETURN
400 REM === move formation ===
402 FOR i = 1 TO ne
404 IF h(i) <= 0 THEN GO TO 420
406 LET sx = fx + e(i): LET sy = fy + r(i)
408 IF sx >= 1 AND sx <= 30 AND sy >= 1 AND sy <= 21 THEN PRINT AT sy, sx; " "
420 NEXT i
422 LET fx = fx + fd
424 IF fx + 10 > 30 OR fx < 1 THEN LET fd = -fd: LET fy = fy + 1
426 IF fy + nr > 19 THEN GO TO 700
428 FOR i = 1 TO ne
430 IF h(i) <= 0 THEN GO TO 445
432 LET sx = fx + e(i): LET sy = fy + r(i)
434 IF sx < 1 OR sx > 30 OR sy < 1 OR sy > 21 THEN GO TO 445
436 LET ci = 4
438 IF t(i) = 2 THEN LET ci = 5
439 IF t(i) = 3 THEN LET ci = 6
440 IF t(i) = 4 THEN LET ci = 3
442 PRINT AT sy, sx; INK ci; CHR$ (143 + t(i))
445 NEXT i
447 RETURN
450 REM === move bombs ===
452 FOR i = 1 TO 3
454 IF o(i) = 0 THEN GO TO 480
456 PRINT AT n(i), m(i); " "
458 LET n(i) = n(i) + 1
460 IF n(i) > 21 THEN LET o(i) = 0: GO TO 480
462 IF m(i) = px AND n(i) = py THEN GO SUB 530: LET o(i) = 0: GO TO 480
464 PRINT AT n(i), m(i); INK 2; CHR$ 153
480 NEXT i
484 FOR i = 1 TO ne
486 IF h(i) <= 0 OR t(i) <> 4 THEN GO TO 496
488 IF INT (RND * 30) <> 0 THEN GO TO 496
490 FOR j = 1 TO 3
492 IF o(j) = 0 THEN LET m(j) = fx + e(i): LET n(j) = fy + r(i) + 1: LET o(j) = 1: LET j = 3
494 NEXT j
496 NEXT i
498 RETURN
500 REM === draw player ===
505 PRINT AT py, px; INK 7; CHR$ 152
508 RETURN
510 REM === enemy destroyed ===
512 LET sx = fy + r(ht): LET sy = fx + e(ht)
514 PRINT AT sx, sy; INK 2; CHR$ 149
516 BEEP 0.02, -5: BEEP 0.02, -10
518 LET pt = 10
519 IF t(ht) = 2 THEN LET pt = 25
520 IF t(ht) = 3 THEN LET pt = 50
521 IF t(ht) = 4 THEN LET pt = 30
522 LET sc = sc + pt
524 IF sc > hi THEN LET hi = sc
528 RETURN
530 REM === player hit ===
534 LET li = li - 1
536 PRINT AT py, px; INK 2; CHR$ 149
538 BEEP 0.1, -10: BEEP 0.1, -15
540 PAUSE 25
542 PRINT AT py, px; " "
544 IF li <= 0 THEN GO TO 700
546 LET px = 15
548 GO SUB 500
549 RETURN
600 REM === draw HUD ===
605 PRINT AT 0, 0; INK 7; BRIGHT 1; "SC:"; sc; " HI:"; hi; " LV:"; li; " W"; wv; " "
610 RETURN
650 REM === check wave clear ===
652 LET w = 0
654 FOR i = 1 TO ne
656 IF h(i) > 0 THEN LET w = 1
658 NEXT i
660 IF w = 1 THEN RETURN
662 PRINT AT 10, 9; INK 7; BRIGHT 1; "WAVE CLEAR!"
664 LET sc = sc + wv * 50
666 BEEP 0.1, 12: BEEP 0.1, 16: BEEP 0.2, 19
668 GO SUB 600
670 PAUSE 50
672 LET wv = wv + 1
674 IF wv > tw THEN GO TO 750
676 GO TO 40
700 REM === game over ===
705 CLS
710 PRINT AT 8, 10; INK 2; BRIGHT 1; "GAME OVER"
715 PRINT AT 10, 7; INK 7; "Score: "; sc
720 PRINT AT 12, 7; INK 7; "Wave: "; wv
725 PRINT AT 14, 7; INK 7; "High: "; hi
730 PRINT AT 18, 6; INK 7; "Press any key"
735 PAUSE 0
740 LET li = 3: LET sc = 0: LET wv = 1
745 GO TO 20
750 REM === game complete ===
755 CLS
760 PRINT AT 6, 7; INK 7; BRIGHT 1; "CONGRATULATIONS!"
765 PRINT AT 8, 5; INK 6; "All "; tw; " waves defeated!"
770 PRINT AT 10, 7; INK 7; "Final score: "; sc
775 PRINT AT 14, 6; INK 7; "Press any key"
780 PAUSE 0
785 GO TO 700
800 REM === define UDGs ===
805 FOR i = 0 TO 13
810 FOR j = 0 TO 7
815 READ a
820 POKE USR CHR$ (65 + i) + j, a
825 NEXT j
830 NEXT i
835 RETURN
840 REM UDG A: drone
842 DATA 36, 126, 219, 255, 255, 102, 66, 0
844 REM UDG B: scout
846 DATA 24, 60, 126, 255, 219, 24, 36, 0
848 REM UDG C: tank
850 DATA 126, 255, 255, 255, 255, 255, 126, 0
852 REM UDG D: bomber
854 DATA 66, 231, 255, 126, 60, 90, 36, 0
856 REM UDG E: bullet
858 DATA 16, 56, 16, 16, 0, 0, 0, 0
860 REM UDG F: explosion
862 DATA 36, 153, 66, 129, 66, 153, 36, 0
864 REM UDG G: double shot
866 DATA 84, 170, 84, 170, 84, 170, 84, 0
868 REM UDG H: shield
870 DATA 60, 126, 255, 255, 255, 126, 60, 0
872 REM UDG I: player ship
874 DATA 16, 56, 56, 124, 254, 254, 130, 0
876 REM UDG J: enemy bomb
878 DATA 16, 16, 56, 16, 0, 0, 0, 0
880 REM UDG K: explosion 2
882 DATA 129, 66, 36, 0, 36, 66, 129, 0
884 REM UDG L: shield icon
886 DATA 60, 126, 126, 126, 60, 24, 0, 0
888 REM UDG M: drone frame 2
890 DATA 66, 102, 255, 255, 219, 126, 36, 0
892 REM UDG N: scout frame 2
894 DATA 36, 24, 219, 255, 126, 60, 24, 0
900 REM === WAVE DATA ===
902 REM wave 1: 8 drones, 1 row, speed 4
904 DATA 8, 1, 4
906 DATA 0,0,1,1, 2,0,1,1, 4,0,1,1, 6,0,1,1, 8,0,1,1, 10,0,1,1, 12,0,1,1, 14,0,1,1
910 REM wave 2: 10 drones, 2 rows, speed 4
912 DATA 10, 2, 4
914 DATA 0,0,1,1, 2,0,1,1, 4,0,1,1, 6,0,1,1, 8,0,1,1, 0,1,1,1, 2,1,1,1, 4,1,1,1, 6,1,1,1, 8,1,1,1
920 REM wave 3: 10 mixed, 2 rows, speed 3
922 DATA 10, 2, 3
924 DATA 0,0,1,1, 2,0,1,1, 4,0,1,1, 6,0,1,1, 8,0,1,1, 1,1,2,1, 3,1,1,1, 5,1,2,1, 7,1,1,1, 9,1,1,1
930 REM wave 4: 12 mixed, 3 rows, speed 3
932 DATA 12, 3, 3
934 DATA 4,0,1,1, 6,0,1,1, 3,1,1,1, 5,1,2,1, 7,1,1,1, 2,2,1,1, 4,2,1,1, 6,2,1,1, 8,2,1,1, 1,1,1,1, 9,1,1,1, 5,0,3,2
940 REM wave 5: 14 mixed with bombers, speed 2
942 DATA 14, 3, 2
944 DATA 0,0,1,1, 2,0,1,1, 4,0,4,1, 6,0,1,1, 8,0,4,1, 10,0,1,1, 12,0,1,1, 0,1,2,1, 4,1,3,2, 8,1,2,1, 12,1,1,1, 2,2,1,1, 6,2,1,1, 10,2,1,1
How It Works
Lines 650-676 check for wave clear at the end of each game loop. A FOR/NEXT loop scans the hit points array. If any enemy has hit points greater than 0, the wave is not yet clear and the routine returns immediately. If every entry is 0, all enemies are destroyed.
Lines 662-670 run the wave clear sequence:
- Print “WAVE CLEAR!” at the centre of the screen in bright white.
- Award bonus points: 50 multiplied by the wave number. Wave 1 gives 50 points, wave 5 gives 250.
- Play the fanfare: three ascending BEEPs.
- Update the HUD to show the new score.
- PAUSE 50 — one second of celebration.
- Increment the wave number.
Line 674 checks if all waves are complete. If the wave number exceeds the total waves, the game victory screen appears. Otherwise, execution jumps back to line 40 to load the next wave.
Lines 42-58 reload by using RESTORE 900 and skipping past earlier waves. Each wave header has three values, and each enemy has four. The skip loop reads and discards all values for waves before the current one, then reads the current wave data into the arrays.
RESTORE and DATA Positioning
RESTORE resets the DATA pointer — the position from which READ takes its next value. By default, READ works through all DATA statements in order. RESTORE 900 moves the pointer back to the DATA statement at line 900.
The wave-skipping approach reads and discards earlier waves. An alternative is to use RESTORE with the exact line number of each wave (RESTORE 910 for wave 2, RESTORE 920 for wave 3, and so on). This requires knowing the line numbers in advance, but avoids the skip loop. The current approach is more flexible — it works even if you rearrange the DATA statements.
Bonus Points
The wave clear bonus scales linearly: 50, 100, 150, 200, 250 for waves 1-5. This rewards reaching later waves. A player who clears wave 5 earns 750 bonus points across all waves. Combined with per-enemy points, the scoring gives skilled players substantially higher totals.
Try This
Adjust the bonus. Change the multiplier from 50 to 100. Does the bonus feel too generous? The bonus should be noticeable but not dominate the score — per-enemy points should still matter.
Add a wave counter to the title. When the game resets after game over, remember which wave the player reached and display it: “Best wave: 4”. This gives the player a secondary goal beyond score.