Literally finished my first play though last night on the middle difficulty, overall very good and makes a nice change of pace from the CoD inspired just keep shooting it will be all ok in the end play style and story, nice to see there is still some respect for the classic brain over brawn franchises.
biggest issue was the afore mentioned boss issue, especially the first one with the player suddenly going from popping off mooks with a single shot from a non lethal weapon or melee strike to suddenly most weapons in your inventory are damn near useless and no melee. then the last boss anded up the near opposite in difficulty
had several restarts involving run few tactical shots and run again, ended up cover shooting him with my laser sighted 10mm in the head for most of a 16 round clip and he died.
The new way they did the significant conversations was also nice, and the xp bonus for non lethal kills was a massive plus for me.