BreakIn is a clone of the classic Breakout action game, coded in 20 lines of BASIC (max 80 chars per line) for the Sinclair ZX Spectrum computer. BreakIn is my entry to the Breakout Basic Challenge, organized by Associazione Culturale RetroProgramming Italia 8 bit e oltre in May 2019. Although the implementation approach has been inspired by Attribute Smash!, the game has been developed from scratch.
In BreakIn, a layer of bricks lines the top third of the screen and the goal is to destroy them all. A ball moves straight around the screen, bouncing off the top and two sides of the screen. When a brick is hit, the ball bounces back and the brick is destroyed. The player loses a turn when the ball touches the bottom of the screen; to prevent this from happening, the player has a horizontally movable paddle to bounce the ball upward, keeping it in play. The player can move the paddle left or right by pessing z or x.
You can either play BreakIn in your web browser (keyboard is required) or download the game (and source code) for usage with a real ZX Spectrum or an emulator from the project page on itch.io:
In case you’re interested, here is the complete code:
1 BORDER 1:INK 0:PAPER 0:CLS:LET L=6:LET S=0:GO SUB 42:GO SUB 30
2 LET A$=INKEY$:LET H=1:IF R=0 THEN BORDER 4:PAUSE 0:GO TO 1
3 IF A$="z" AND A>23200 THEN LET A=A-1:POKE A,40:POKE A+3,0:GO TO 5
4 IF A$="x" AND A<23229 THEN POKE A+3,40:POKE A,0:LET A=A+1
5 LET D=B-A+31:IF ABS D<3 THEN LET W=-1:LET V=SGN D:BEEP .03,12
6 LET W=(Y=0)+(Y<>0)*W:IF X=0 OR X=31 THEN LET V=-V:GO TO 10
7 LET U=B+W*32:IF PEEK U THEN LET T=U:LET W=-W:GO SUB 40:IF Z THEN LET V=-V
8 IF H*V*PEEK(B+V) THEN LET T=B+2*V:LET V=-V:GO SUB 40:IF Z THEN LET W=-W
9 LET U=U+V:IF H*PEEK U THEN LET T=U:LET W=-W:GO SUB 40:IF Z THEN LET V=-V
10 POKE B,0:LET X=X+V:LET Y=Y+W:LET B=B+V+32*W:POKE B,56
11 IF Y=21 THEN LET L=L-1:BORDER 2:BEEP .5,-23:IF L=0 THEN PAUSE 0:GO TO 1
12 IF Y=21 THEN PAUSE 25:BORDER 1:GO SUB 42:POKE B,0:GO SUB 32
20 GO TO 2: REM *** BreakIn 20-Liner Breakout by Marco Varesio 2019 ***
30 LET A=23214:LET R=0:FOR I=1 TO 7:FOR J=22562+32*I TO 22589+32*I
31 POKE J,I*8:LET R=R+1:NEXT J:NEXT I:LET V=1:LET W=1:GO SUB 42
32 LET B=A-31:LET X=A-23200+1:LET Y=20:POKE B, 56
33 FOR I=0 TO 2:POKE A+I,40:NEXT I:RETURN
40 FOR I=T-1 TO T+1:LET R=R-SGN(PEEK I):POKE I,0:NEXT I:BEEP .02,23
41 LET S=S+1:LET H=0:LET Z=PEEK(B+W*32+V)
42 PRINT #1;AT 1,0; "Score: ";S,"Lives: ";L-1:RETURN