Bong Joon-ho’s “Mickey 17” is bonkers in ways that initially delighted me until it wore me down and overstayed its welcome.

Bong’s first film since winning the Oscar for his international success “Parasite” (2019) is the kind of big-budgeted, wildly ambitious overreach that a major studio would only give someone who found monster success and wanted to cash in their chips.

While “Mickey 17” isn’t bad, it’s not a great work, either. I’m glad I saw it on the big screen and there are plenty of individual moments to savor, but sitting through the entirety of this admirable failure to get to them is not something I’ll be doing again soon.

Robert Pattinson plays the title character, a citizen of Earth in 2054, who has run out of luck and stupidly signs his life and rights away by joining the space program. Mickey has agreed to being the “expendable” on a voyaging starship, a stooge who willingly puts himself in danger in the name of research and exploration.

The one upside is that Mickey can be cloned after every grisly death, though what sort of life is this? When a mishap occurs and somehow allows Mickey to avoid death at the hands of an alien species, referred to as “creepers,” things get even more complicated and dangerous for him.

I was in the film’s corner for the wonderful first half, which balances pitch-black comedy, amazing visual effects, a nihilistic view of humankind and, at the center, a Pattinson performance and character eccentric and interesting enough to provide the film’s center.

Once we get to the main concept of the story (which the hilarious 2022 source novel, “Mickey7” by Edward Ashton, got around to setting up much faster), things go off the rails. By the time we get to the endless, hideous dinner scene and a belated jailbreak sequence that both go on far longer than necessary, everything on the screen feels like an endurance test.

There’s just too much here, and that goes double for the performances by Mark Ruffalo and Toni Collette as the sham religious cult leaders of the spaceship. A little of this would have gone a long way, but both actors are giving turns best suited for a “Saturday Night Live” sketch.

Instead of coming across as villains I loved to hate, both actors give performances so broad that I grew embarrassed.

The intended political satire, reflection on a cult mentality and an allegory for colonization is so heavy handed, I wanted “Mickey 17” to, pretty please, stop screaming in my ear and get back to being a tragic comedy about how human beings place value on the lives of others.

All the promise of the early scenes are unmet, though far too many subplots (such as a love triangle, business with a loan shark, fractured friendships and even a literally last-minute attempt to inject horror) obscure the stuff that works.

Bong is, indeed, a visionary filmmaker and there are elements here that will stay with me. That said, the film that reminded me most from his impressive body of work isn’t the thrilling futurist humankind-is-doomed fable “Snowpiercer” (2013) or the perfect monster mash of “The Host” (2006) but Bong’s semi-misstep, the similarly over-cooked and tonally wonky “Okja” (2015).

While “Okja” is slightly better than “Mickey 17,” they favorably share a creature feature premise and unsuccessfully shoehorn an unsubtle contemporary message, and also feature a reliable actor hamming it up (though the performance Jake Gyllenhaal gives in that film, as uneasy as it is, holds up better than Ruffalo’s Razzie-worthy turn in “Mickey 17”).

Here’s a mild spoiler – Denis Villeneueve’s brilliant early shocker “Enemy” (2013) is far better at exploring the dangers of meeting one’s double, though the general details of the premise were also better portrayed in “Edge of Tomorrow” (2014) and “Source Code” (2011).

Both the spare, thoughtful “Moon” (2009) and the big, delightful “Oblivion” (2013) tower over “Mickey 17” by portraying similar ideas but managing not to overcrowd the narrative with too many supporting characters, bloated scenes that don’t work and explorations of theme that don’t require jackhammer, don’t-you-get-it messaging.

Look, a great movie just tells its story and has us talking endlessly about it after we’ve seen it, whereas a movie that force feeds us a blatant message, no matter how well intended, comes across like the director is sitting next to us, blaring a bullhorn in our ears.

There’s some of the latter in “Mickey 17,” when all I wanted was the focus to be on Pattinson’s typically risk-taking performance and intriguing character.

Considering how many endings this has (each sporting a different genre and a pleasing Pattinson haircut that suggests a reshoot) and how unpleasant much of this is, it’s no wonder that the release date wound up getting pushed back for years.

Part of me admires the hutzpah of Bong, Pattinson and Warner Bros. for sticking to this cracked vision. The other part of me just wants to have fun and rewatch “Edge of Tomorrow.”

Two Stars (out of four)