My mistake. At first when I opened the game it looked like I could just kind of walk around aimlessly forever (it wasn't clear that there was a goal/ where I was supposed to go, I missed that line in the description). As you said, adding an arrow would have helped a lot.
I have now beaten the game (apples :-) )
It was also a bit hard to tell what counted as walls since they were only a few pixels big, maybe the thickness could have been a bit more? I'll update my rating :)
Glad you like my tutorials ;-)