Got a good bit further in and beat the Steamworks boss. Gotta say, so far this game really has constantly improved as it has gone on. The Ruins area is neat but you can also tell it was one of the earliest areas conceptualized, then Snowdin gets pretty good as the team seems to also figure out more fun NPC interactions. Then the Dunes are suddenly an entirely new area with its own customs and history, which is super cool to see, the bosses become more interesting and there's a lot of characterization to be found, as well as the first hints at the overarching plot.
The Steamworks then are a bit lighter on the NPCs, given that they're abandoned and all, but I still love the vibes. Feels a bit like Old Aperture from Portal 2 to me, with the optimistic attitude towards a future that never shook out like that. And the robots were pretty great, too. The vending machine is a particular favorite of mine. The end boss of the area was also great, and I think the different Soul mechanics really improved after their first attempt in the rhythm miniboss, which suffers largely from a poor controls setup.
This point is also when the story seriously starts to unfold. I'm playing this game simultaneously with my GF over a Discord call and it's immensely fun to theorize and put the pieces together as things are happening. It's honestly kinda brought me back to 2015 when UT first came out, or 2018 and 2021 with Deltarune.