Yep, that can happen if there is a hole in the map architecture. Whereabouts were you, if you can recall? I'll correct it for the next release.
I suppose the fence around here is missing?
Oh, and amazing entry btw.
Seriously, at glance I thought this were the actual commercial game for GBA.
and when I looked at the size of the ROM, which is more than 24 MB, I was like “what in the world?”