Usually overshadowed by its spiritual successor ―Dark Souls― Demon's Souls is perhaps the most important game From Software has ever created. Sure, the DNA of mysterious and punishing dark fantasy world was already taking shape in their previous King's Fields series, but Demon's Souls was the cornerstone for every "souls" game. For once, it features some of the best level design ever put in a videogame, with open spaces mixed with intrincate corridors, traps, secrets, verticality, shortcuts... It patented the brilliant online hint system managed by the players, the anonymous co-op and PVP integrated into the game's lore with invocations and rewards for helping/killing others. And of course, the deliberate combat and difficult bosses that are challenging but can be beaten if you pay enough attention. It doesn't have the fully interconnected nature of Dark Souls but it was well structured with The Nexus as a hub to connect every world via the archstones. Each world was unique, not only in its visual design but in its level design too. Especially the Latria Tower, one of the best designed scenarios ever in any interactive medium.