6/10.
Fractale's plot is nothing basic. It was a very good idea but it was definitely not well executed. You have to think your head off to even remotely understand what's happening, but even then there are still just so many plotholes.
Why can Clain's dad control a doppel to live with Clain when the old man wasn't in an Active Zone?
Why did Dias let Phyrne live all that time if he knew she was the key?
Why does the Fractale system have to be rebooted every 1000 years?
Why does Fractale's brain think like a 10 year old when the girl ('god') used to construct it is 16?
Why did the girl ('god') act like a 16 year old in the last video she recorded and not a 10 year old?
Why was Clain able to safely return home from outer space?
Why did the girl after the fusion have Nessa's voice if she has Phyrne's voicebox?
Why did the girl after the fusion have a completely different personality to the girl ('god') in the video?
This anime wants you to take it seriously, and I did. Now I have all these unanswered questions. I can list way more but I can't be bothered because there'll be 10x as much (not a hyperbole). Yes, you can formulate theories but there's absolutely nothing in the show that definitively answer these questions. In other words, it's one of those anime that pretend it's real deep, philosophical and all, but ends up not knowing what to do. In the hands of a better director and give it some more episodes, its ideas can easily make it an 8/10.
What does this sound like? Oh, that's right. Angel Beats. I gave that a 6/10 too, didn't I? For the exact same reasons. I think it's the score this anime deserves for trying to be a serious anime with tons of plotholes.