Demon's Souls
The game is AMAZING. Holy, it's good. First souls game I played. I wasnt able to figure out parrying in Sekiro, whether the game wanted me to parry as soon as the symbol popped up, before the swing, during the swing or right before the hit. So I started with DeS instead. I really like how the game works. You keep items you find, you lose the equivalence of XP points, when you die. You restart at very clearly defined and chose checkpoints in the game. There is no saving or loading, you are forced to play ironman. Death is part of the game mechanics. It's kinda like soft roguelike mechanics. In later souls games your healing items are very limited.
I cant believe I missed out on this game. My only criticism is that you should find more items. Like just more clothes to wear.

Fuck, this game is amazing. It's kinda like a roguelite. I like that it's linear and not open world. The dragon was scary. It would probably have terrified me as a child. I like how gameplay-centric it is. You can't exploit bosses with terrain abuse, because they all have dedicated arenas. It's the complete opposite approach of other games during it's time.