Slightly disappointingly, it's not a continuation of the first New Stage movie. There's no Cure Echo. It's just another All Stars movie, this time starring 32 PreCures from the ten seasons up to Doki Doki.
Fortunately, though, it's also good. You don't need to know all about PreCure to appreciate it, although obviously that would be a plus. You could even show it to adults, if they didn't mind something that's obviously a children's show, e.g. the fairies' kiddified character designs. It's not just fight scenes. It has a character-based plot. Its main character is a young fairy with attitude called Grell who badmouths the PreCures, has a timid friend called En-En and is going to turn dark.
Grell finds a chained-up forbidden chamber. A sinister voice is calling from there. You and I would know what not to do in this situation, but not our anti-hero.
Where do the PreCures come into this? Answer: Grell and his new friend (called Shadow) invite them to a reunion party. Shadow owns a textbook on all the PreCures, so he's worked out tricks to counter everyone's powers. All the PreCure teams are included... except Doki Doki. I was starting to wonder if they were in the film at all, but they appeared after fifteen minutes. They're the newbies, you see. The series had only started airing a month before this film was released. They're not in Shadow's book.
Our protagonists, though, are Grell and En-En. Yes, we have a film about fairies. PreCure fairies. Goofy-looking fairies with their stupid voices and their annoying tag phrases... and, impossibly, this works. Our heroes make bad choices, but grow. (En-En's growth is almost more dramatic than Grell's, in fact.) They're not evil. Grell's a braggart and show-off who doesn't understand what he's doing. En-En's merely spineless and lacking in confidence... but Shadow's right when calling him almost as guilty as Grell. "You saw what we were doing and did nothing to stop it."
I approved of the film's choice of which PreCure teams to highlight. On one level, it's bending over backwards to be fair. This is right and correct. However choices are unavoidable, because someone needs to say dialogue and star in important scenes. You can't share that out between 32 girls. In order of importance:
1st = SMILE. When this film was released, Smile had just finished its popular 48-episode run. It's their film more than Doki Doki's. They're everywhere here. Cure March gets the coolest bit in the big boss battle, for instance, although both teams then join up.
2nd = DOKI DOKI, whose newbie status gives them a unique plot role.
3rd equal = FUTARI WA, who've become the spokesmen for the older PreCures. (Shiny Luminous gets a big moment!) I was happy.
3rd equal = HEARTCATCH, because they're the best. Erika's still funny, of course. (Her faces! The "dong" on her headbutt!) As for Sunshine and Moonlight, them fixing the sun isn't far from portraying the PreCures as gods. (Would Itsuki be a solar deity like Ra, Surya, Apollo, Amaterasu, Aurora, etc.?) I enjoyed this too.
4th = EVERYONE ELSE. They all get to be cool.
It's another good All Stars film. It's not just a dumb superhero team-up, like the DX films. (I enjoyed that trilogy too, but I prefer New Stage.) It's also very PreCure, with a positive message for both Grell and En-En. It doesn't have The Music, alas, but Grell might well be the best baddie in any All Stars film.
I'd still recommend watching all of PreCure before watching this, though.