First of all, game has a great concept with this retro sci-fi style, interesting variety of weapons, and true tactical gameplay, but...

How the hell should I deal with Doomsday Generator in command room in final chapters?

I do not want to do it on lower difficulty, so I am asking how is it possible on normal?
Generator appears in first turn and no matter what you do, it starts with half map already taken by its range in second turn.
There are too many monsters to use stealth, since they look at all sides.
They even does not matter, because when you reach current range of generator, then you already get instant kill on any character, and range of explosives or EMP is not enough to reach the target.

I already tried Google and YouTube, no one made anything about this level yet.
Thanks for any help.

Ok, I found solution, but it looks too easy and generally like cheating, so I guess it is not a solution intended by devs.
Since "psycho" John has ability that let him live with 10 hp when he gets one "death blow" per turn, it seems he is immune to generator damage if he does not get other damage per turn.
So, I wait until generator destroys all monsters and then send "psycho" John to destroy it, because his health stays 10 each turn.
Is it really how this mission should be done?

You can also use heal buffering and the defense matrix (possibly the energy converter but I'm unsure) to advance close enough and fire EM at it. The developers can feel free to correct me if I'm wrong here but I think the intended solution to any mission is to beat them however you like.

I've beaten the game so if you want any help on later missions feel free to ask.

So "it" gets into Gloria, goes through the portal, and the end?
Did they want to make the player unstatisfied, because the whole game was for nothing?

I was dissatisfied with the ending as well. An epilogue for the rest of the cast would've been nice but with the ending they throw at everyone I guess it's better that there isn't one.

Regarding the DDG towards the final. There are a few more solutions.

Combined with the suitable weapon, Singer has the ability to take control over a character given she uses the right weapon. With the right neuromod she can ghather enough moral power while stealthing around and in position and do it as soon as the situation asks for it...lol. There will be a grenadier right next to the DDG at the bridge (left side seen from entrance).
One can also combine the swap teleporter, the teleporter and defence matrix to come near enough to destroy it with the last breath of consciousness. Of course, one as to bring the right weapon for this as well.

I played a version where the DDG was placed after one turn after the battle startet. Sop1I can't really follow with "appears in first turn".