YMMV / Fall of the Crystal Empire

• Broken Base: Some like it for its action and Visual Effects of Awesome. Others dislike it for its writing and characterizations.
• Fridge Horror: It's implied that it was Luna (as Nightmare Moon) who is the one that banished the Empire and not Sombra, and that Celestia thought it was Sombra because Luna couldn't properly explain it herself.
• Hilarious in Hindsight: Sombra's controversial Adaptational Personality Change (from a distinct No-Nonsense Nemesis to a more-stereotypical Smug Snake) and ending (overshadowed by another villain). Years later - the show's Season 9 premiere would give him similar Characterization Marches On, and have him serve as The Scapegoat for the rest of the Villain Team-Up.
• Nightmare Fuel: Princess Luna becoming Nightmare Moon, especially on how chilling and slow it becomes.
  Luna: I..am The Nightmare.
• They Wasted a Perfectly Good Character: Some found the lack of success Princess Celestia had in the fight and having no part at all in defeating King Sombra a missed opportunity.
• They Wasted a Perfectly Good Plot: There's an implied war happening when Sombra took over... and we don't see it. Heck, we don't even see the Empire disappearing.
• Visual Effects of Awesome: It's Silly Filly Studios! They can do no wrong with the visuals!