I wasn't particularly enthused about seeing Men in Black 3. It's production was a disaster - they started shooting without a completed script in order to get Will Smith and then shut down for months to figure out the rest of the story - and nothing in the trailers begged my attendance, though Josh Brolin's mimicry of a younger Tommy Lee Jones was apparent even in the few syllables the trailers showed. But my girlfriend wanted to see it more than Avengers and was paying, so away we go.
The story itself is pretty thin: An extremely nasty alien named Boris the Animal ("It's just Boris!" he frequently barks) has escaped from a rather unique prison and somehow gone back in time to kill Agent K (Jones/Brolin), forcing Big Willie to also go back in time to try and prevent history being changed and the Earth's destruction. I'll give you exactly one guess as to whether they succeed.
To their credit, they don't just go back and revisit the same characters from the first two movies and there's a twist involving a famous person whom you'd expect to be an alien based on how these movies work. (Whoops! The trailer gives it away. Weak. I'd missed that or forgotten that detail.) Brolin kills it with his channeling of Jones; Emma Thompson gets some fun moments; there's an alien with the ability to see alternate timelines that's a different type; there are a good assortment of gags and laughs.
However, Smith seems flat - not tired in a jaded character sense, but because he's too old and too removed from his early persona. If you look at his resume, you realize it's been a decade since he's played what we recall as the typical Fresh Prince role. I've seen reviews saying Jones looks like he's wishing he wasn't here, but it's Smith who seems reluctant to retread old riffs. (It's like what Eddie Murphy would be like reprising Axel Foley or Reggie Hammond.)
Overall, we could've easily lived full and complete lives without Men in Black 3 in them, but even as a cynical cash grab, it's not militantly offensive and has enough fun to make it worth a watch eventually.
Score: 6/10. Rent it.