I'd heard it was bad, but I hadn't realised it was unwatchable. It's trying to be a CGI-heavy action blockbuster, at which it fatally succeeds. It's blockbuster nonsense in a blender. It only comes alive intermittently as an actual film, with characters and any kind of human level to what you're watching.
Gatchaman, incidentally, is a famous 1970s anime franchise that got sold internationally as Battle of the Planets, G-Force: Guardians of Space and Eagle Riders. It had superb animation, decent writing and lots of violence that had to be edited out of the English-language versions. This is not that anime. Instead it's a live-action film released approximately to commemorate the franchise's 40th anniversary. CAVEAT: as usual, what I'm saying here is just my opinion. There will be lots of people who think I'm being all hoity-toity and thought this film was good fun. I'm happy for them.
I'll start by summarising the film's first half-hour.
Fire hell apocalypse world because GALACTOR. (They're the villains.) "Give me that stone." Giant death wheel lands in modern Tokyo. Baddies shrug off military attacks and kill soldiers, but then GATCHAMAN arrive for Extremely CGI Superhero Fight Scenes that go on and on. (The CGI's quite well done, but the film's not even trying to make this sequence feel like anything except absurd CGI super-action. Consequence: it's like watching a video game.) The audience check their clocks. Couldn't the film start slowing down soon? Have we already been watching for twenty minutes? I want to breathe! I want to care about some characters!
27 minutes: for the first time I felt I was watching a story.
The film improves after that. There's some emotional content in a flashback from five years earlier. However this film's idea of progress is to get up to the level of a thin James Bond film. Having been at "utterly empty" for nearly the first half-hour, they eventually improve up to shallow action movie cliches and a plot made out of all the most obvious ideas that a teenager would think of first. There will be a space station that wants to zap cities on Earth with its superweapon. There will be "Virus X". There will be the supervillain Berg Katse, with exactly the plot role you'd assume from a formulaic blockbuster if you've spent even ten seconds reading about him/her on wikipedia.
Is there anything good here? Well, I quite like the cast. You wouldn't call any of them special, but they're full of energy and enthusiasm. Even Tatsuomi Hamada stops being annoying as Jinpei once you get to know him. They don't make the film good or watchable, but at least they're in no way disgracing themselves, which is more than you can say of what's around them.
The film also uses the franchise's iconography. It had to, really. Will the Gatchamen get to turn their ship into a firebird phoenix? (Yes, which is cool enough that you almost don't notice that they've done so as a fan gesture after everything's almost over, in a way that doesn't actually achieve anything.)
This film is one of many Gatchaman reboots over the years. (Gatchaman Crowds the same year is excellent, incidentally, although you'd need molecular analysis to detect more than the slightest traces of Gatchaman in it.) It's also worthless. I'd sooner watch famously bad Japanese live-action anime/manga adaptations like Devilman and Casshern (both 2004). Those had some personality. They were misfires, but at least there's something there to chew on. This, on the other hand, is simply trying to be a dumb blockbuster. That's the beginning and end of its ambition. It succeeds more terribly than anyone could have feared.