10 CLV:CLS
20 FOR X=0 TO 30
30 ?CHR$(1);
40 NEXT
50 FOR Y=1 TO 21
60 LC 0,Y:?CHR$(1)
70 LC 30,Y:?CHR$(1)
80 NEXT
90 FOR X=0 TO 30
100 ?CHR$(1);
110 NEXT
120 FOR Y=2 TO 20 STEP 2
130 FOR X=2 TO 28 STEP 2
140 LC X,Y:?CHR$(1)
145 'IF !INKEY() CONT
150 R=RND(4)
160 A=0:B=0
170 IF R=0 A=-1
171 IF R=1 A=1
172 IF R=2 IF Y=2 B=-1 ELSE GOTO 150
173 IF R=3 B=1
175 IF SCR(X+A,Y+B) GOTO 150 
180 LC X+A,Y+B:?CHR$(1)
190 'IF !INKEY() CONT
200 NEXT
210 NEXT
300 X=1:Y=1:LC 29,21:?"G":CLT
310 U=X-BTN(28)+BTN(29)
320 V=Y-BTN(30)+BTN(31)
330 LC 0,23:?TICK()/60;
340 C=SCR(U,V)
350 IF C=1 GOTO 310
360 LC X,Y:?CHR$(0)
370 X=U:Y=V
380 LC X,Y:?CHR$(249)
390 WAIT 6
400 IF C!=71 GOTO 310
410 LC 0,0:CLK
420 END