I’m unfamiliar with the series, what aspect would cause Phil problems?
all of it. combat system is kinda complicated, it uses a radial wheel, so you can attack your enemy at top left, bottom right, middle right, center, top north, bottom south, etc etc. doing techniques is about inputting specific combos, for example I had a move that specifically targeted the enemies wrist to make them drop their sword, to do this I had to do like, top right, bottom right, middle right, middle left.
saving requires having savior schnapps in your inventory which is consumed on use.
in the first game henry was illiterate and physically could not read unless you found an NPC to teach you. unsure if he will start the second game literate or not, I assume so.
lock picking was pretty complicated, didn't use the skyrim system, had its own unique thing.
there are no waypoints to quests that I recall, just a marker on the map and a general "search area" type thing, there's also no fast travel in the traditional sense. best you can do is set Henry to "auto travel" across the map, but you might get ambushed/attacked and forced to deal with that.
one of the quests locks you into having sex with a wench, you have no say in it, if you start the quest you ARE cumming in that wench.
wearing things like a helmet massively obscures your vision, not wearing a helmet makes your brain easy to bash in.
haggling had a tutorial that was like 2 pages long and filled the screen with text from what I recall.
in order to do alchemy, which I personally loved, you had to follow essentially a cook book which told you things like "ok, put the powder in the bowl, crunch it 6 times, then boil it for 12 seconds, then distill it" the game did offer you the option to skip this process, but you get less good potions and shit out of it.
that's everything I can think of off the top of my head. basically Kingdom Come was a game that was very heavily focused on immersion and realism, to the point it made you do a lot of stuff by hand if you wanted best results.