This was shit. Terminator series is probably fucked beyond repair but this is such a japanese/anime take on Terminator with your usual (tired) anime exposition claptrap about humanity's self-destructiveness, whether humanity deserves to survive, AI, fate etc. Now don't get me wrong there's elements of this in the good Terminator films (T1 and T2) but fuck me, the japanese are always overdramatic, bogged down in trite exposition that pokes holes in it's own logic (they start discussing the complications of time travel and timelines) and can't seem to view AI without persistently anthropomorphising it.
Not to mention that the terminators in this seem to weigh the same as a human and can be slowed down with your bare fists but invincible apart from that.
The thing that makes the Terminators a terrifying villain is that they are literally emotionless unstoppable killing machines with no sentience only looking to achieve their programmed goals, even Skynet has a certain lack of sentience even if it is described as "self-aware" (at least in T1 and T2) because it can be argued that it's just performing as intended but because of human oversights it lead to disastrous consequences. (It's programmed top priority was probably to defend itself at all costs. Like how in Deux Ex, the AI Daedalus, was created to identify terrorist organisations and then inadvertently designates it's creators as terrorists because they fit the pattern recognition of a terrorist organisation because didn't code themselves as an exception.)
There's no point psychoanalysing why Skynet decided to nuke humanity, just that through inhuman calulation and pure cold logic, it decided that it was the best outcome according to it's programming. It's not really the scope of the Terminator franchise, nor should it be. The termiantors and skynet are just an incomprehensible black box that can't be bargined with.
If the anime is taken as "robot skeletons from the future" it's a generic-as-hell passable anime timewaster: 4/10. As a terminator product it's overly-familiar and misses the point of the first two films: 3/10