After completing every dark souls game, Bloodborne, Sekiro, and Elden Ring. Demon's Souls was the last on my list to try, and boy did it live up to my expectations. Visually this is probably the most beautiful game I've seen in my life, mechanically it runs so smoothly and has some of the most fluid movements I've seen in a souls game aside from Sekiro. The animations, sound design, lighting, and boss designs are just a couple things I can go on about. But my main thing was the atmosphere. Every area had its own unique feeling. The Valley of Defilement felt hopeless and terrifying, like you were in a hole you knew you would die in. While Boletaria castle felt like you just missed the era of a kingdom in its prime, fallen to demons who feasted on the souls of the living. You play as a slayer who traveled to these lands for the same reason a lot of others did. To kill these demons and take their souls, as the power of a demon's soul is beyond that of human imagination. The game does an excellent job at truly making you feel like you're the last sane person left in this dreary hellscape. However depending on how you play, even you may not be sane.
