Well for starters, the cast is brilliant; Paul Rudd is perfect as this everyman kinda guy who also is a bit of a cat burgler, he has some great comedic lines and has good chemistry with the rest of the cast. Michael Douglas is an awesome Hank Pym , he does the dramatic moments excellently and even pulls off a few jokes too. All the other cast were great as well but I do have to mention Michael Peña, he delivers some of the best lines in the movie and is an all-round entertaining character.
Next I'll come to the story. Much like the superhero himself, this plot is scaled down tremendously compared to the other films of the MCU. He's not unearthing a huge government conspiracy, he's not guarding the galaxy and he doesn't have to deal with an apocalyptic A.I. robot; Ant-Man is a heist movie which takes almost a civilian view of the rest of the world, and that's what makes this movie stand out I think. Of course you get references to the Avengers but this really does feel like a small event we're looking into, like a side mission in a game, and I enjoyed that.
Being a Marvel movie the special effects would of course be top notch but Ant-Man goes beyond and has some really breathtaking visuals, the shrinking/growing effect is awesome and the shots of Ant-Man when he's small are so photo-realistic because they blur out all the background and it really does look you've entered this tiny world. The action sequences were pretty impressive as well, some of the best in the franchise, because of his powers they used some very clever ideas to make it very entertaining.
Now for some of the negatives of the film. Mostly the first half; there were some clunky exposition scenes and it just seemed to go really slow in parts; of course they need to explain a lot to new audiences but for some, if you're not that interested or you already know it all then I've heard people call it boring. I for one wasn't bored at all but I did feel the need for the pace to get going a bit. Another negative was the villain; Yellowjacket was fine, he was awesome, menacing and cool to watch but the character controlling it, Darren Cross came across as bit cliche at times and just wasn't generally threatening as a person.
In the end Ant-Man was very funny, very clever and one of the most unique films of the franchise. Be sure to smile at the obligatory Stan Lee cameo and stay through the credits all the way to the end. I give it about 9/10. Check out more of my stuff at The OJ Reviews!