Originally Posted by Corintis

I don't know why the hell it took me so long to figure out that the stages with unused pathways and panels are actually drawing various Halloween pictures, like cats and whatnot

Oh that's awesome! I didn't even notice until you pointed it out. I saw the extra paths and wondered what they were there for. I was so focused on function, I didn't think to stop and admire the view.

Here's what I see:

->Open Spoiler<-

E14-01 Witch's Hat
E14-02 Skull
E14-03 ?
E14-04 ?
E14-05 Carved Pumpkin
E14-06 Lolipop, candy in a wrapper, candy cane
E14-07 ?
E14-08 ?
E14-B1 Scythe
E14-B2 Cat
E14-B3 Spider

If the Advanced and Ultimate maps are also pictures, it's not obvious to me what they are.