I'll start with the things I enjoyed.
I liked the animation.
The environment created was something not often done and that was refreshing, also the ability to create something from nothing reminded me of FMA which was nice.
Soooo now the things that I believe let this anime down.
Story....or lack off. Personally not a big fan of episodic stories and prefer something that is actually going somewhere. Yes there were flashbacks and plenty of them (ugh) but they were often just conveying the relationship between the characters, with a small amount explaining certain circumstances of how they got to where they are.
There was also an issue with pauses, something new to me and hope I don't experience it again. Couple of characters would be having a conversation and then when one asks a question there's this sudden long pause. It's like someone paused the show and god is it irritating, that being said much of the dialogue I found was drivel.
Also there doesn't seem to be much on character development. You get the many flashbacks of how they came to where they are but going forward or some sort of goal just seems to be lacking. Heck I'm pretty sure there wasn't an objective unless I missed it.
So yeah, the premise get a pass but the lack of story and actual character development kill it, which is a shame because it looked promising.
Overall I would recommend it to people I hate.
P.S. Now that I think about it, this anime kinda felt like watching fillers...