Ah yeah, I need to block off the top left of the map until I can figure out how the original game calculates room entrances and exits. Basically the gamemaker source code for the original puts the whole map in one giant room, and I'm still trying to reverse engineer how some of the view transitions work. Thanks for letting me know!
If you get stuck in the top corner, I think you should still be able to hold A+B to warp out