Is Agartha S on the Switch the same game as this, or are there significant differences?

I've had this game on my Switch for around a year now, finished it quickly when I got it. I recently opened it back up and rediscovered my frustration that I simply COULD NOT find a way into cell D7. I have scoured every pixel of the surrounding cells, and found no entrance of any kind. This game is so niche I can find no support online whatsoever. Please help me, I'm going insane....

I don't really understand how to fight the boss at H-8. Doesn't seem like I have enough firepower to do anything meaningful. There was a sign at H-7 I think, saying there is another sign somewhere that tells me how. So, how do I complete H-8? Can it be done with Gunner\all characters?...

Unversioned update (24/6/2021) XInput controllers can now be plugged in after launching the game first. Version 1.4 (24/4/2019) Updated various graphics in the game. Unversioned hotfix (20/3/2019) Fixed an apparently corrupted sound file that might cause the game to crash when changing in-game options. Version 1.3 Steam release version. ...

It was easy to find a doorway from E-1 to E-2, but that warped me to the next row on the map. Shouldn't there be a doorway from E-1 to F-1? I don't see it anywhere, yet this should be the most obvious path. If I'm supposed to be bouncing around all over the map, this needs to be more clear in the instructions....