The last 25 minutes work. They're not great and they're being dragged down by Star Twinkle, but at least they have a point.
The rest is a waste of time.
There's one character here who works. That's Mary Ann, the dog cop from ep.36 of the TV series. She has a dramatic goal and some charm... but she's little more than a cameo.
I'll summarise the plot. The girls have a pointless fight because that's mandatory, then the film starts ditching redundant regulars. (Five PreCures is too many, of course. I could have told them that.) Blue Cat disappears with Mary Ann, but unfortunately returns. She's still the least-featured of the five girls, though. Elena and Madoka get written out so clumsily that it's funny, as they reveal that they're going on a field trip to Okinawa tomorrow. (They hadn't mentioned this small thing to Hikaru and Lala. What the hell?)
Having whittled the cast down to two, the film introduces an extraterrestrial blob that can only communicate through facial expressions. Hikaru names it Yuuma. Our heroines then ignore TV news of mysterious shooting stars last night, since that couldn't possibly mean more aliens were visiting the Earth. Ahem. Our heroines go on a tour of cool tourist spots, then have more pointless fights. There's character business for Lala, hobbled by the fact that Lala's never really worked as a character. There's something slightly hollow about her. I don't dislike her, but it's always been like watching a hole in the script where a character should have been. This film gives her good scenes, but there's a missing connection because Lala has no core.
This drags on for over 45 minutes.
The film comes alive after that. We learn what Yuuma is. The Lala-Yuuma story reaches its conclusion, which is a song. I actually like the Star Drop and the "wonders of Planet Earth" thing, but that's it. I'd have probably liked the film had it starred functional characters instead of Hikaru and Lala, though.