Finished the game on hard yesterday so here is my verdict that will hopefully help everyone who is still on the fence:
* If you want a challenge definitely choose "hard" - anything below might be way too easy
I think that the difficulty definitely changes the way you play the game: As every hit you take is actually punishing on hard you really have to block, counter and be very concentrated overall. Still think that many people don't get the game because it's NOT your typical action/hack&slay experience.
* Finished in about 7 hours havn't touched MP yet
* Observing your enemies and blocking is key, as is the healing ability - I think that the core gameplay is actually quite good - it's the lack of OTHER satisfying activities that really really hurts the game in the end
* Thus it's advised to play the game in short sessions as it doesn't get as repetitive
* Story isn't above average for a videogame: It's basically Gladiator the videogame but on a much more basic level. Life-like faces really help to sell an otherwise unremarkable and predictable plot. In other words: It's the presentation that sticks out not the story itself.
* Set-pieces are top-notch, some vistas are simply mindblowing.
* Graphics are in a league of it's own. Some of the best I've ever seen, PC included. Only downside: Very linear levels, some missing effects ([some] water/foliage not reacting to player movement).
What really annoyed me was the small number of models for both friends and foes. EVERY f*** roman soldier looks the same including the same body height and overall physique. With a game that looks that good it really puts you out of the experience because you feel like fighting for a clone army not human beings. Barbarians are the exact same thing, a little bit of visual variety would have helped tremendously. As it is it sometimes looks comically bad.
* Overall I really enjoyed the ride, however I couldn't shake the feeling that there was a TON of potential untouched and thus a lot of opportunities missed. This is a very weird game that feels polished (graphics, presentation) and very rough (lacking variety) at the same time, it's a love-hate-thing.
I feel good with my purchase in the end because I want to support this (potential) franchise. Ryse is a controversial start but as a whole package it's promising.