I just finished the game. What’s your status? Did you finish or drop the game long ago or are still playing?
I didn’t quire understand all the plot points at the end. But I think that’s mostly (though not completely) because the plot is quite complicated, not because of the language. I bought the English version both to lend out and for when I replay the game. The story is the kind that one would want to revisit as everything will look different after all the revelations. And I’m sure there are a few things I would better understand in English.
Thoughts about battle mode
I think it’s an interesting game. But the font was horrid for me and I basically didn’t read the descriptions 
. That kind of technical language is also more difficult for me than the language in the story. I also don’t like the abstract presentation. I would prefer the enemies to look more like they are supposed to look in real life. The tripods look life flying enemies when they are ground types.
Thoughts about adventure mode
I really loved the middle part, where we learned slowly puzzle together that there actually isn’t any time travel, it’s just teleportation between different cities “themed” for different time periods.
I didn’t quire follow all the stuff towards the end. Like the motivations of the different Morimura’s.
I didn’t quire like the revelation that it’s all basically virtual reality, because: I didn’t see it coming and I thought it was revealed too late, I wasn’t sure if that really makes sense, it cheapens the “time travel is really transportation” plot twist while not being nearly as original, and it kinda makes everything feel less real.
(I did think for a moment it might all be real, but everyone are robots, with the protagonists remote controlling them, and the rest being controlled by AI)
But I guess it makes sense. Matrix style virtual reality seems more physically possible than star track style teleportation or deceiving a whole city into believing there is an outside world. One thing that I find suspicious is all the nano machine and drugs stuff. How does taking medicine in the virtual world even affect the biological body? But since the biological body needs to be regulated and fed anyway, it kind of makes sense that eating, drinking, sleep, medical treatment etc in the virtual world affects the biological body.
(And what was the thing with Amaguchi(?) being “outside” the whole thing?)
I was kind of expecting the end to be a bit of a let down. But they actually provided a somewhat lengthy and satisfying ending and “prolog”.