Very funny and adorable! I loved how everyone played a role in the story, and even showed new sides of the Mane 6' personalities from their own ideas to break through the castle. Shining got some much needed development, it's honestly nice to see more of him and to know that Twi and Shining never always got along (no cadence is seen either actually). Same deal with Luna and Celestia, we get to see them both argue like sisters again, and it is so hilarious. And the plan between Luna and Spike is great too.
And little tidbits like baby Spike, baby Apple Bloom, Maud, Zephyr, etc.. All of it is unexpected, and it's what makes it so fun. This was a great 200th episode