Platyborg has 2 metal hands until he punches Perry at the end, where his right hand is real. Then as he walks back through the portal, he has 2 real paws with metal braces.
During the fight with the evil Norm-bots, every creation that Phineas and Ferb made during the show up to this point is showcased, including the Santa Sleigh they made for the Christmas episode; however that shouldn't be here as chronologically that episode hasn't happened yet.
When the two Doofs appear as Lone Ranger and Tonto, the reins of Tonto's horse appear in the middle of the shot.
Olivia Olson is listed in the end credits as providing the voice for Vanessa, but the character does not appear in the film.