So, we start with an otaku protagonist who is completely detached from humanity. He is a genius programmer with an infatuation for plastic toys. He loves them so much, to the point the only thing he says when he dies is how he won’t be able to play with more toys, instead of how devastated his family is going to be by his death. You are instantly made to know he places machines over people.
He is then reincarnated into a magical world with no explanation, where, conveniently, the plamo he loved in our world are huge mecha in this one. With some convoluted logic, because he loved playing with them makes him able to know how they work better than anyone else, while still being a kid. That also somehow makes him able to build, pilot, and upgrade them faster than anyone else. And then he goes to have a fun adventure as he fools around with them, while the natives of that world are dying by the millions during wars and monster invasions. Yeah, it’s completely messed up.
As you will probably notice right away, the only reason there is reincarnation in the show, is just so they can excuse in the pilot episode why the protagonist is an overpowered psychotic kid. It plays no part in later episodes and he doesn’t address it anymore. So basically, they slapped the isekai premise because “hey, it’s in-fashion so let’s use it.” It’s obviously there to pander the ever growing number of otakus who wish they could escape reality by getting transported in a game-like world, where they are awesome and everybody loves them.
And this is what you have to understand from the get-go with this show. It’s not about mecha or action or suspense, as it is empowerment fantasy for those who have a fetish for plastic robot toys, as well as androgynous boys. Because that is what the protagonist is; an idealized trap, loved by both genders for how awesome he is. If for some reason you can’t handle the non-stop over-praising of his skills, this is not a show for you.
As you can probably guess by now, there are no memorable characters besides the trap MC. Whether it’s love interests, military officers, mindless CGI monsters, or enemy soldiers, all others are there for validating how awesome he is all the time for living in the fantasy of his dreamy hobby. And the MC has no complexity or depth; he is just a picture perfect self-insert power house, having fun while piloting robots, making robots, laughing while fighting monsters with robots, or getting angry when monsters destroy robots (and not the people they kill). He is instantly a better pilot than anyone else, he has girls loving him for looking like a girl, he is laughing at moments when others are screaming in fear, and acts like a complete madman. It’s disgustingly self-indulgent.
I could spend a few paragraphs on stuff like the setting or the visuals, but they don’t matter in the least. As long as you are fine with this sickening premise, you won’t give a damn about anything else. Aside from that detail, it’s a complete throwaway show, with nothing special or worthwhile to look back once you somehow manage to finish it.