So here's my recommendation for good long lasting single player games.
For ps4 exclusives:
Nier automata and Horizon zero dawn. Although im not sure about how long they are, they are imo one of the best single player story driven games. They also boost an awesome gameplay too and lastly, gorgious scenery (although nier is not really your typical beauty). Nier also has one of the best OST in the history of video games.
Days gone is also fairly good. Good looking scenery, good gameplay and a (imo) decent story.
Bloodborne is also a good option if you can handle souls-like games. Imo its the best souls-like games. It is also highly recommended to buy its dlc if you are going for it. The dlc is more than worth its price. But fair warning in case you dont know souls-like games, its hard and it can punish you for the smallest things.
Not exclusives:
Although i guess its not really long, Devil May Cry 5 is an awesome ride. Like the first 2, awesome gameplay and scenery. It also boosts an OST that can rival nier (although way less in quantity).
Red Dead Redemption 2 although i havent really played it, just heard of the reviews.
Actually the rest of the souls-like games. Dark souls 1, 2 and 3. Dark souls 3 is the best out of these 3 but still not as good as bloodborne but its good enough to be worth playing. Now there are 2 odd cases, sekiro shadows die twice and demon's souls (ps3 exclusive).
Sekiro is without a doubt the hardest souls-like game. Its mechanics and gameplay feel and look awesome. However playing, you will soon realise that the game has some infuriating things. To give you a quick update, all souls-like games (barring nioh actually i have no idea about this game at all) have your currency be dropped when you die (and picked up if an enemy is close, dark souls 3 and bloodborne). If you die you can just find the location where you died and retrieve back your currency. Thats not the case for sekiro. Sekiro has, what it calls unseen aid, where when you die you have 30% chance of not losing sen (money) and exp when you die. Now when you die you lose a portion of your exp and sen (not sure how much i think half?). Each time you die there is a chance a shit will spawn in your inventory, hurting npcs around the game and lowering your unseen aid. That 30% will become (with one of those shits) around 15%. The next shit will lower it to 13%. Then 10% and then 7% (not sure whats the lowest). Now the reason why this is bad mechanics is because its fucking random whether unseen will proc. And because you need exp to get new skills you have to be extremely careful when you farm because once you lose them, you cant retrieve them back.
Then there is also the fact that the game is saturated with mini bosses. Like for real it took me so long to find the first boss. By the time i found her, i have already faced 4 mini bosses. Like you find one mini boss, you spent time learning his moves and eventually you kill him. You are happy to move on finally, only to see in the next room to be another fucking miniboss. Only this time he has his whole personal guard around him. So you have to avoid him while you dispatch his guard on secret. And AFTER you kill them you have to learn this new boss. But if you die you have to refight them again. Also did i mention that these simple mobs hurt like hell and they can kill you with ease? Did i also mention that early on your healing pots are extremely limited? And like if this wasnt enough these mini bosses have 2 fucking hp bars. Granted you can sneak attack them to take one out but that is not possible with all minibosses.
Sorry about this rant i just really really dont like sekiro how it turned out. Ignoring these two the game is actually decent. If you can endure the above outliners and like extremely difficult games sekiro might just do for you.
Demon's souls is extremely old and i dont remember it quite well. Because of that its not so good mechanic wise as the rest souls-like games.
