I can't seem to move up in the following Lightbike game (copied mostly from this site's version). The game ends when I do, as if I've "crashed" and I'm not sure why. Any help would be much appreciated.
:Full :FnOff :AxesOff :0→Xmin:1→ΔX :0→Ymin:1→ΔY :ClrDraw :Vertical Xmin :Vertical Xmax :Horizontal Xmin :Horizontal Xmax :60→A:92→B :2→C:2→D:25→G :Pxl-On(A,B :Pxl-On(C,D :Text(-1,28,31,"READY? :Pause :For(E,26,36 :Line(29,E,67,E,0 :End :Repeat G=45 or not(pxl-Test(A,B) and pxl-Test(C,D :getKey :If Ans :Ans→G :A+(Ans=34)-(Ans=25→A :B+(G=26)-(G=24→B :1+pxl-Test(C+1,D :Ans+(Ans=2 and pxl-Test(C,D-1 :Ans+(Ans=3 and pxl-Test(C-1,D→F :C+(Ans=1)-(Ans=3→C :D+(F=4)-(F=2→D :Pxl-Change(A,B :Pxl-Change(C,D :End :AxesOn :ZStandard :ClrDraw :ClrHome