"Phineas and Ferb's Musical Cliptastic Countdown" is something of a different episode for 'Phineas and Ferb'. Instead of having two or three subplots involving Phineas and Ferb, Perry and Doofenschmirtz and at times one with Candace following the same formula, this is a countdown of 'Phineas and Ferb' songs. With a subplot involving a very unlikely partnering on paper and a pretty different Doofenschmirtz scheme. Did worry though that it would be too much of a clip-show and be too much of a "cheater".
As well as being different, "Phineas and Ferb's Musical Cliptastic Countdown" is thankfully both interesting and enormously entertaining. It was great to see such great songs included in the countdown and all deserving to be there and there was nothing pointless about the episode. Really appreciated that structurally "Phineas and Ferb's Musical Cliptastic Countdown" did something different from the usual 'Phineas and Ferb' episode, while maintaining all of the show's spirit and never losing it.
The animation is bright and colourful as always and the character animation and expressions are fun and nicely varied. The theme song is still infectious and quotable. The writing is full of wit and intelligence throughout, especially with Doofenschmirtz and Monogram (at his most interesting in a while), whether in the songs or in the plotting centered around them, and the pacing is lively.
Character writing, especially for the never less than very amusing Doofenschmirtz, and voice work are excellent. Dan Povenmire always sounded like he was having fun as Doofenschmirtz and is a joyous presence here too. The Monogram and Doofenschmirtz story sounded very unlikely on paper but is very interesting. Doofenschmirtz is fantastically nuts as usual.
Best of all is the music, crucial as the music is what the episode centres around. The music has always been one of my favourite aspects of 'Phineas and Ferb', and there were many fabulous songs throughout the show's run. All the songs here deserved to be in the countdown, actually would have made a fuss if "Ain't Got Rhythm", "Little Brothers" and "Busted!" weren't there, and are fantastic. "When We Didn't Get Along" from "It's About Time" was a surprising omission though, if to nitpick.
In summary, wonderful. 10/10.