TL; DR: The series had great potential with interesting storyline and characters. However, it is extremely rushed and underdeveloped which takes away a lot of the enjoyment. The art (as expected from Kentaro Yabuki) is definitely the best point.


No Spoiler Review

I think Darling In The FranXX has a really good and original idea with a fine cast of characters. The build-up is interesting and the story develops well, there are good humour and romance.

However, the development is extremely rushed, a lot of details are left out and backgrounds of characters are hinted but then completely left out. The ending is unclear and also extremely rushed and a lot of the relationships between characters are left hanging mid-development. I found this seriously intimidating and it ruined the series for me.

The only satisfying conclusion is regarding the two main characters. At least their story is told well. Also, the series is filled with cliches and overused plot structures which are irritatingly predictable.

Maybe I am too harsh but I really think the series didn't live up to its full potential.

ART

The best part for me is the art - Kentaro managed to nail facial expressions, emotions, details, and dynamics.
STORY

The story, as I mentioned, starts strong but then goes completely downhill for me.
CHARACTERS

Also had a lot of potential for great development and interesting background reveals, however nothing of this sort happened except for the two main characters.