Volume is bugged and don't make distinction between background music and voices,
english translation is often not quite correct or cutted (dub based), as for all the remaining languages are mtl
(I guess except jap and perhaps chinese).
After playing for a while I can confirm that the game is seriosly bugged, you can complete it? I guess yes, however there are many many things that need to be corrected, starting from the translation is often lacking quality with typical mtl errors for genders but also repeating phrases and some no sense (other than as i said before sometimes is cutted or uncorrected), it have some logic structure so i guess was made by an IA however be aware, here and there you will find also some untranslated stuff.
Talking about bugs a major one is during the fights, as being a side scroller the worst that could happen is that the enemies spawn over the walls and that's exactly what happen making you going back and forth in hoping that they will follow you, unfortunately this is not always happening making you shoot blindly.
During fights if you happen to die there will be a H scene, a dream of some sort, problem is that if you die while shooting the fire shoots will be loop all over this event making it very annoying.
NPC are really a mess, not only they speak no sense but often they will get caught while you are talking to quest dealer making everything really confusing, it might happen also that they will interfer while you are trying to get access into a building making the icon disappear, in this case you have to wait them to leave the zone and also you need to get outside the trigger since the icon is no longer there.
Time is a characteristic of this game, unfortunately the game run at 2x (or more) making the timer skip seconds, this might be a big problem during the invasions since instead of having 5 min to to fight numerous waves you get only half time (or less), since you might be also at the other side of the map getting over there might take also quite a few (just to take notice the game have a teleport system even if isn't explained, just open the "phone" and select "send" ).