Ant-Man is not exactly as well known as Spider-Man, Iron Man, Wolverine, or heck even most Marvel heroes to be honest. He however was a founding member of The Avengers in the original comics along with his wife Wasp. However they were not founding members when it came to the movie version. Though I wasn't too surprised to see the story of Ant-Man make it to The Avengers movie universe.
The film first begins in 1989 where Hank Pym resigns from S.H.I.E.L.D. after they try to recreate his technology without his blessing. He was capable of making a suit that could make the wearer super-strong and super-small. Believe the power was too dangerous to leave his control, he decided to hide it away. Which eventually causes him to have a distant relationship with his daughter Hope and his former protege Darren Cross. Hank is horrified to learn that Darren is building a yellow jacket suit which is based on similar technology of his Ant-Man suit.
Hank is far too old to wear the suit anymore, and he doesn't want Hope using it either. So he finds a talented (but out of luck) man named Scott Lang. He believes Scott can be trusted to be the new Ant-Man. But even when he masters the suit, they'll all the help they can get if they are to stop Darren Cross and his technology. If they fail, then the whole world might fall prey to an endless amount of super-villains.
Overall Ant-Man was about what I had expected. Not nearly as good as the best Avengers-related movies, but not one of the worst either. Ant-Man has always been a rather boring super hero but I think having Hank pass the torch in this story-line helped the story. I thought Paul Rudd, Micheal Douglas, and Evangeline Lilly all played their roles perfectly. I also thought Corey Stoll (who I remember as Peter Russo on House of Cards) did a very good job playing the super-villain Yellow-Jacket.