how about a haunted maze? guests get scared by spooky themed features. custom maze sections with custom sprites showing monsters hanging around the paths, in the walls, or flying above, or something. there could be special sections that look like they are walkable by guests, and when a guest approaches what would appear to us players as a monster doing monster things, the guest does a jump scare (like when deciding not to enter a queue line for something too intense) and turn around because it's actually a dead end.
there could also be regular custom maze sections for wider, crooked/banked, or zigzag paths, stairs or sloped paths, tunnels (as mentioned above) etc.
there could even be futuristic theming, and the maze could employ portals to teleport guests from one part of the maze to another.
thinking about it, there could be custom maze theming and special pieces for almost all of the different theme sets.