What a guy who shrinks and talks to ant is fantasy in a way super-soldiers, and capitalists in powered armor may not be. It's a a child-like fantasy; one where everyday items become hazards and improvised weapons. A running bath tube creates a tidal wave; a flying ant becomes a steed. It's ridiculous only in the way that Alice in Wonderland or the Wizard of Oz is ridiculous. Ant-Man is just a hero it's hard to grittify credibly. It's stuff too much fun.
if you like the Marvel films, you will like Ant-Man. Marvel Entertainment has their formula (for both better and worse) down to a science. The beats are similar and the humor is there. The review talking points (Perhaps passed out by the production company. They've done it before.) highlight how comedic it is, but I don't think it's really any more comedic than say Iron Man III. It certainly isn't a superhero comedy like The Green Hornet. Likewise, reviewers will say it's different from the other Marvel films because it isn't about "saving the world"--which ignores Pym and Lang saying that's exactly what they're out to accomplish.
So ignore all that stuff and just enjoy. For the Marvel Comics fan, you get a hint of Hank Pym's Cold War secret hero career. You get to see the Wasp's finest hour. You get a glimpse of the Microverse--excuse me, Quantum Realm. A decade ago, it would have been hard to imagine any of that on the big screen.
The best stuff is the shrinking stuff, though. The special effects look really good and there are a couple of nice set-piece battles between shrunken combatants. The ants have character, too, even if the mix of species is a strange one for the film's location.
It's not perfect. There are some nonsensical bits in the script, that may have come from different versions being stitched together. Is Lang a recidivist criminal cat burglar or a mechanical engineer that burgled a dishonest company just once for revenge? Is Darren Cross made crazy by Pym particle exposure as everybody keeps saying even though we haven't seen him have any particular exposure until late in the film? And there is other stuff.
Fridge Logic, for the most part. These things won't bother you when you're watching one inch tall guys hurl toy trains at each other--and that's really for the best.