in the crossroads of fate - spaceport event, futaba has mentioned that certain elements has been combined between both palaces. here’s what I remember:
castle: prison of love prisoner consisted of women instead of the volleyball team ; library consisted mainly involving kiuchi; pushing crates
museum: video camera gimmick
bank: spike traps and moving razors seen inside miyazawa’s palace
spaceport: robot gimmick ; reddish atmosphere was similar in katayama and akashi’s palace
lab: button gimmick found in the second half of katayama and Akashi’s palace
however, I can’t find what elements were used for katayama and akashi’s palace for the pyramid arc. was it the three poison murals?
The optional minibosses within each arc, and I think some of the treasure chests, take the form of the corresponding Palace that Wonder was going through in the main story at the time. For instance, here's one of the optional minibosses in Part 4 of the Pyramid Arc:
It's clearly one of the shadows from Katayama/Akashi's Palace!
The Pyramid Arc does seem to have the fewest elements from its corresponding main plot Palace, though, overall.
