Darling in the FranXX is a sci-fi mecha anime which takes very heavy inspiration from Neon Genesis Evangelion. It is directed by Atsushi Nishigori, who also directed the iDOLM@STER franchise. Studio Trigger and A1 Pictures are working on this project together, which is a move for the worse. Studio Trigger is known for its over-the-top senseless shows which are style over substance, however, A1 Pictures is a very corporate business that focuses on outputting lots of profitable shows and has no real identity in the things they make. The show is scheduled to run for 24 episodes.
Unfortunately, but also predictably, my impressions for the first episode are negative.
The first 5 or so minutes are insufferable and pretentious internal monologue by the protagonist, Hiro. It gives a bit of exposition into the rules of the world like mechs requiring a male and female pilot, but for the most part it can only appeal to edgy teenagers and emos. There's no reason to sympathise with a slightly depressed kid when he is introduced with complaints and self-pitying lamentations. The heroine is introduced as a powerful but mischievous pilot who ends up with dead partners frequently. She doesn't have much of a personality in her introduction but it gets worse once she meets the main character.
For no real reason other than because the plot demanded it, Hiro and the heroine, known as 002, happen to be in the same area. Hiro is being pretentious and gloomy and 002 is skinny-dipping for no reason other than to entice the 14 year old viewers. Hiro immediately displays a lack of integrity and intelligence by picking up 002's underwear lying on a tree. 002 emerges from the water, flippantly walks around naked while Hiro ogles at her body and teases him for holding her underwear while she is still naked. This indicates what sort of tone the show is planning to take: fanservice with a stupid main character that has to say things out loud just to make sure that the viewers know. This is demonstrated earlier where there is blood on a window and Hiro has to touch and smear the blood on his fingers to determine whether it's really blood or not. He follows this unnecessary procedure with the "It's blood" line. It should be quite clear that this is aimed at 14 year olds and if you're past that age you're either immature or weird for liking it.
The plot of this episode is so heavily influenced by Evangelion that it gives the impression that more effort was put into the visuals than into the writing. Considering Studio Trigger's previous works, this is likely what happened. Hiro's former partner, who must be whisked away for sucking at her job, lectures Hiro about not running away (like Shinji) and has some self-pitying emo emotionally manipulating moments before hopping onto a transport and promptly being crushed by a not-angel-from-Evangelion. The monologue-before-death trope is a cheap trick to pretend that there are stakes and that the viewers should feel emotion. There is no reason to feel anything but annoyance at how rushed the sequence was. Trigger/A1 jumped the gun on this one.
The threats are differently designed angels that threaten the human encampment and must be defeated. Normal weapons like cannons are totally ineffective, raising the question of why anyone would invest that much money into high technology arms, and the only thing that can stop the not-angel is a FranXX (renamed Eva unit with very similar interior but it has a transformation sequence). The blatant copying of Eva is frustrating to watch because of the total lack of creativity. The not-angel is soon defeated by Hiro and 002 who team up and, despite Hiro's inability to pilot which was remedied by 002 kissing him and triggering a power up (fanservice and empowerment fantasy), defeat it within seconds. This is an atrocious writing decision and is a big red flag to anyone watching. This can only mean that either: every other pilot is pathetic, or the not-angels are laughably weak. Both of these possibilities ruin any illusion of tension and lower the stakes dramatically.
If you were planning on picking this up you should make a change of plans. Watch Evangelion instead if you have not already seen that. If you have already seen Evangelion, watch it again. Darling in the FranXX stinks of a low-creativity Trigger project with A1's corporate business decisions which will hamper the quality in exchange for good marketing and mass appeal. I will watch this through to the end and write up whether you should watch it or not. Don't waste your time like I am doing.