These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Phineas and Ferb The Movie: Across the 2nd Dimension
Alternative Character Interpretation: Did Doofenshmirtz-2 really turn evil because he lost that toy train? Or did he have a past so unbelievably traumatic that he blocked it out, and funnels all those negative emotions into the loss of his beloved childhood toy? Or was he a horrible person even as a kid and is just using the train as an excuse?
Genius Bonus: Or, perhaps, Liberal Arts Major Bonus - Norm's "Get me! I'm a Georgia O'Keeffe painting!"
Ornithorhynchus anatinus, the scientific name of the platypus, is among the lyrics of "Everything's Better with Perry".
Existentialism trading cards!
"I'll trade you two Kafkas for a Dostoevsky." From Buford!
Getting Crap Past the Radar: In Robot Riot there is the very blatant line "cause your sister is a fridge and you know her light is always on!". They just called that metaphorical sister easy on a Disney cartoon.
Hilarious in Hindsight: For years, there have been tons of fan art and fan videos on YouTube showing Phineas and Isabella kissing. Then this movie comes and does it for real.
Doof-2. He rules parallel Danville with an iron fist as a dictator, with an army of Mecha-Mooks (thankfully some relief given that they are based off of Norm) led by a familiar platypus that you now see has turned evil against his own will. He forces everyone to conform, as well.
The robot dog Phineas rides during the Robot Riot scene, named Rover in another episode, may look a quite a bit disturbing from certain angles.
They Wasted a Perfectly Good Plot: What? No Vanessa (Original and Parallel) and/or Parallel Stacy? No Parallel Stacy is even more of one when you realize that her absence is justified since Parallel Candace's "growing up" so fast probably made it so that she never met her world's Stacy, which makes the plot an even bigger waste because Original Candace and Stacy never bring that up or reflect on it.
In a way, they already used that plot with Parallel Jeremy (While she did meet him, she thought of him purely as a soldier, rather than a possible friend or boyfriend like she would have had she not had to grow up so fast.) Throwing in the same thing with Stacy would have wasted time without adding much.
And there was going to be a few scenes with both original and parallel Vanessa, but they had to cut them out due to timing. You can watch said deleted scenes on the DVD.
What an Idiot: Our Doof once built an army of robots just like Doof-2, except he 1) installed self-destruct switches and 2) placed them on the bottom of their feet so no one would be able to reach them. One step later and...