Just found out that the “goto” function is actually implemented in Picotron; I’ve tested a pico8 code snippet by @ultrabrite and put it into the usual function _draw()

function _draw()
cls()
x=1 y=0 n=120
::io::
d=rnd(2)>1 and 0 or 5
line(x+5-d,y,x+d,y+5,11)
x+=6
if(x>n+6) x=1 y+=6 print(' ')
if(y>n) y=n
flip()
goto io
end