This is also not a stricte action-anime, same as mecha, there's cool action in it, but it's not the main focus.
What is it then? Well, that's a bit more difficult of a question, drama probably is the closest of genres, but I can definitely say what the focus of this anime is. Character relationships.
If you approach it as a mecha/action you will be sorely disappointed and miss the point completely, it's about the characters discovering their emotions, fighting against them, trying to live with them, hide them, show them, come to terms with them or deny them. Not spoiling anything but more likely than not if you're around say 20 years old and had a few emotional encounters with the opposite sex you might see some of your own early mistakes in actions or thoughts here and really relate to the characters.
I've seen some people shitposting about shameless fanservice in this anime. Sure this anime is lewd quite often, but if you get immersed into this curved mirror of a world, you'll notice that the fanservice is there just to lighten the tone and then most of the time to build something serious or even heavy upon it, which in my opinion is quite a novel and fresh take on it (once the tone changes within the episode fanservice is gone too).
It's easy to dismiss this anime as "stupid" or "simply fanservice" if you take that approach from the start, just watch one or even half an episode without paying attention. You have to suspend your disbelief and give it a go, try to get into the characters heads while watching it. I myself was high alert when approaching this series, I dislike vast majority of the mecha series (especially Evangelion, goddamn Shinji get in the bloody mech already!), but after watching only one episode I was instantly captivated.
If you like animes where characters and their emotions take center stage, definitely try DitF, you shouldn't be dissapointed. If on the other hand you're looking for some light-hearted fun for some popcorn munching I don't think this series is for you.
