Here's the plot from what I gathered: Mila Kunis is suddenly the majesty of the Earth and has to protect it from a bunch of rich douchebags that live in Jupiter's atmosphere who want to use it for harvesting grounds or something. It's a dumb plot, and every scene that tries to move the plot forward is a scene wasted. The only interesting parts of this movie are the visuals and Channing Tatum's character, but even he is given absolutely no character development. He's just a badass space agent, or something. I don't even remember.
The characters end up the same way they began - there was no journey to redemption or revelation for anyone. It was just do this, do that, stop this, go home, the end. And they try to include multiple stories, like Mila Kunis' relationship with her family (boooring); Caine (Tatum) and Stinger's (Sean Bean) history (wholly underdeveloped), the whole villain arc...
The villains in this movie are spoiled brats. Seriously. They're not scary, they're not intimidating, there was no point in the movie where I was like "oh man sh*t is about to go down"; there was just no intrigue. Their motives were all over the place. It's not worth trying to piece together every plot point they throw into the movie because it will just lead to confusion and disappointment, and eventually frustration when you realize how much potential was wasted in creating this massive universe. The lizards looked really cool. Why not have more of them? Oh we're just going to focus on the playboy brat now, okay.
I really wanted to care about this universe. It has a Star Wars vibe in parts, like the "royal" wedding scene and the space battles, but there were no good characters to experience this adventure with. You're just watching things happen with no consequences, or at least none you cared about.
The acting was fine in this movie. Channing Tatum and Sean Bean in particular gave great performances, and Eddie Redmayne as the primary antagonist was decent as well. Yeah, he's an Academy Award winner, and as much as I hate to say it I have not seen The Theory of Everything yet but I loved him in Les Mis so I was really hoping he would save this movie. Unfortunately the material he's given is absolute garbage, so in an effort to make the character stand out, Redmayne give him a weird, eerie, whisper voice that was akin to a hundred year old man trying to force words out from the back of his throat. But hey, I think it worked. The guy is completely unlikeable so might as well give him a unique trait to remember him by. Good on Mr. Redmayne because he succeeded. The only things I will remember about this movie are the cool visuals, the wasted potential, and his creepy voice.
Don't see this movie. Unless you want to see some really great CGI for a couple hours, which can be found in much better places by the way, you won't find anything worth salvaging from Jupiter Ascending. It was a nice effort but ultimately a swing and a miss.