This one's very memorable and special to me, but utterly for reasons outside of its storytelling and narrative design. As a writer, I tend to approach games in that way- Bear with me, I'll talk about things other than words in a bit.

Lucas Pope, I feel, does well with creating emerging stories through branching paths, heavily influenced by player action. In "Papers, Please", for example, it was extremely compelling to have little stories for all these people passing by your checkpoint, unfolding either on-screen or in your mind. After all, your decision of "APPROVING" or "DENYING" their visas was an incredibly meaningful one in the lives of these bit-characters! However,
even back then, dialogue-writing and scene-construction were not exactly Pope's forté, and there wasn't much meat to the characters' bones (partially because there were so many). That wasn't a huge problem when the micro-narratives the game created were so dependable.

"Return of the Obra Dinn" definitely does not play to the strengths as a storyteller that "Papers, Please" made apparent; it's a fairly linear game where player agency in the story is starkly reduced (considering that the game's story takes place in a past you interface with from the present through magical flashbacks). Obra Dinn is also divided into individual areas that, while variable in the exact sequence of the scenes within them, end up following each other in the same order every time.

By the way: Obra Dinn has an enormous cast, all of them named and uniquely designed - while continuing to underwrite each of them, worse even than the few consistent and familiar faces from "Papers, Please". It feels like you barely get to know anyone; the windows you see them through are so brief and so limiting. You have no agency in these people's lives because they're either already dead or otherwise gone. The game feels extremely dead because of that, to its detriment. In a game with a stronger horror-component, that feeling would've been compelling; here, it's kind of dull.

Then, there are some of Lucas Pope's historical and political beliefs that subtly seep into the writing and character designs; never becoming ghoulish, but never being particularly tasteful in its depictions of people from distinct cultures, nor of complex political circumstances drenched in blood (such as the East India Company); it attempts to ride a strange line of fantastic pulp and historical precision, where each side diminishes the other. (As an aside, I still struggle to forgive Pope for his toothless and dull examination of the "circle of revolution" in "The Republian Times". It's a jam game, I know, but c'mon.)

TL;DR:

Why does the game still stick with me. then?

The deduction mechanic in 3D-space was genuinely beautifully executed. On your first playthrough, there is so much to see and discover in these static scenes from the past; Obra Dinn absolutely is a game for people with a love for detail, and - guilty as charged, that'd be me! It's also very good at capturing a feeling; an era of computer games that's long-past, one that never played like Obra Dinn, but definitely felt like it.

Overall, I'd say it's a worthwhile thing to go into entirely unspoiled. It'll give your brain some good exercise for an evening or three, and despite its flaws (all that shit up there + the 1-bit style being maybe not ideal for a detective game), it really is a game you remember.