There ARE games that the Dark Souls comparison is apt when indeed a game is very closely aping the structure of From Software's games. I shall list some games where this is accurate for Greg's sake because nobody else on the podcast is willing to actually read between the lines on that.
*NIOH is very much a Koei Tecmo take on Dark Souls in contrast to the sort of character action games that they themselves attempted to innovate on when Itagaki was still running the show there and not shopping Devil's Third around. the combat, the level design, the mechanic of dying and dropping your currency/experience is all there.
*Salt and Sanctuary is very much a transplant of the gothic look and feel, the weighty combat with emphasis on blocks and dodge rolls, and general tone of dick-headedness to the player that I'd argue isn't so much dickheadedness as it is attempting to teach the player through failure.
I can see it a liiitle bit with Hollow Knight bieng this drab but butiful world of spoopy undead medival bugs and what-not, but Hollow Knight doesn't seem to have weapons you find that VASTLY change your playstyle or attacks that are so slow and weighty that you have to commit to them fully."
In all seriousness, I urge Greg to take the dive on Dark Souls Remaster whenever it hits during this nebulous Summer release window. I think the design will hearken to all the parts of castlevania he loves. <3
To Jon's point though, the original Dark Souls features level design that loops back in on itself. you're not nessessarily finding new abilitieds that let you access areas you couldn't before, but you ARE finding keys or opening up doors that are normally one-way doors that loop back to checkpoints, and the world has a very interconnected feel. I feel like the original Arkham Asylum would much better translate to being a metroid game if you squished it into 2D, whereas Dark Souls would be more akin to like... River City Randsom, maybe? I'm tryign to think of old 2D games that have interconnected worlds that you don't nessessarily gain new abilities to unlock parts of the map, but rather just find keys that open doors or maybe the rare occasional item that does such? maybe Metroid 1 where the real only things gating you from exploring everything are the morph ball, bombs, and maybe the high jump boots? I can think of exactly 2 instances where you get any sort of traersal tool in Dark souls and both of those are 100% optional.