When Phineas is trying to "wake up" out of the Christmas situation, he makes a remark about how different things would be had he never woken up that morning. This is similar to the fate-altering wish in this film.
During the song "Danville for Niceness", the sign says "Danville for Niceness or: Santa, What Gives?", which is similar to the end of each Rocky and Bullwinkle show where two titles for the next show would be announced, usually puns of each other.
During the closing credits, Phineas and Ferb and friends can be seen dancing in the same manner as the Charlie Brown kids in their Christmas pageant rehearsal.