instead of clearly being repetitive and stating the two extremes, I will place my opinion here
Phineas and Ferb is a rather interesting show, while it is rather childish at times. It is one of the few shows that I actively am interested in because I find it interesting.
Unfortunately, I do not think that the movie was as incredible as everyone thought it was. While I did enjoy it, I feel that Phineas and Ferb is becoming far too predictable, and this movie was no exception. I was hoping at one point there'd be some sort of explanation for all of the contrived coincidences, but there wasn't one. After a point I decided just to go with it, like the rest of the show, and enjoy it.
In the end, I would definitely recommend watching this if you like P+F, but I was hoping it would be less like an overly long, if dramatic, episode.