I've recruited Hellhound.
Well I didn't get the achievment cos I defeted Khan the alpha golem in Normal mode and changed to hard mode just before winning. With what I had at this point (level of characters, gear..) I was near from getting the hard mode achievment.

I don't have a save of it, I'm in chap 3.
I'll try my best in a second playthrough.
I've went until a fight after a wall, looks it's quite tough.
Do you get one romance achievment per playthrough or can you get one romance achievment and get a next one later in the game, having worked on several romances?
Does a romance achievment bring the game to its end sooner?