Plot hole: After the secret passage has collapsed, the Black Fox hires Hawkin's midget acrobat friends because the only opening left "is barely (wide) enough for a child". Yet, during the throne room brawl, Hawkins passes the swing-around rope to a guy who is much taller than the midgets.
Plot hole: Princess Gwendolyn puts the key for the secret passage into her cleavage for safe-keeping, but when her father shakes her with each praise for her supposed loyalty, the key comes loose and falls to the ground. However, since the key is hidden inside her cleavage, it should slip down under her dress and fall to the ground between her feet whilst remaining hidden by her skirt. Instead, upon the clinking, the key is seen right in the open, in front of Gwendolyn's skirt.