It's... ok! The trailer for Ant-Man is leaning a little heavy on "this is going to be a redemptive journey" and not as heavy on "this is funny and fun" as I might have hoped - it's certainly not up there with that magical first Guardians of the Galaxy trailer. But the seriousness of the trailer is essentially a set-up for the joke at the end, a sign that the movie won't be taking itself too seriously (but will have plenty of serious plot). Also, check out Paul Rudd topless and hot in this trailer. That Marvel magic strikes again.
What I liked best was seeing the suit in action. When I was on the set of Ant-Man I got to see Rudd in costume and it was very cool, but all lit and color-corrected the suit looks even better. I am a very big fan of this design, which nods to the classic while not feeling impossibly retro.
Also worth noting: the line "It's not about saving our world, it's about saving theirs," which speaks to the stakes of the movie - it's not an end-of-the-world riff again, but rather about securing the future. This is a film about fathers and daughters and legacies. So those who are sick of big, city-destroying climaxes in Marvel movies will find Ant-Man a real breath of fresh air.