After finishing up with Jedi: Fallen Order a few weeks ago, I picked up Sekiro and started playing it. Over the last month and a half, I have put in over 75 hours into the game, and am at the end of the third game cycle (NG+2), and have completed all achievements.
This game is seriously awesome - it is incredibly challenging at the start as you try and learn the game mechanics. Enemies have two "bars" - vitality and posture. Vitality is their health, and can be defeated by dealing sufficient damage. Alternatively, you can also defeat enemies by filling their posture bar through proper deflections and counters (hitting the enemy also fills the posture bar). Once an enemy's health is depleted or their posture bar is filled, they become vulnerable to a "deathblow", which allows you to kill the enemy (regular mobs do not need a deathblow to kill, but all minibosses and bosses need one or more deathblows to defeat).
There were certainly a few "walls" (i.e., bosses) that took many, many attempts, and early on I was getting frustrated (Juzou, Lady Butterfly, and Genichiro were the three early bosses that gave me some trouble). However, eventually it 'clicks' and you learn to properly deflect the attacks (the game heavily emphasizes deflecting over dodging) and to defeat the enemies.
The game world is very well designed and thought out. One of the late-game areas is seriously one of the most breathtaking and beautiful areas I have ever seen in a video game. The story and narrative is also quite good - like most FromSoftware games, not all plot points are told to you explicitly and you will have to some exploring and reading to get all of the lore.
One early issue I was having was that I was struggling playing the game with a controller. Having played all of Fallen Order on KB/mouse, I read some comments indicating that people preferred Sekiro on controller, so I opted to start playing it on a controller. I found it difficult to control and react properly, so I switched to KB/mouse, and I found it substantially easier to control and to play. The game works fine on KB/mouse and all keys are fully re-mappable.
Highly, highly recommended.