Tumblr is still around?

It’s got a top-down CRPG view (similar to the Fallout 1/2), but Avernum: Escape from the Pit might fit thematically.

You end up in an underground fantasy world where “undesirables” are sent to by a corrupt empire.

Another option would be Underrail. Another top down CRPG, this time based in a post-apocalytic world where everyone lives underground. The world building is top notch and the combat is very well developed with lots of choices (it’s a also IMO a hard game). While the world building is strong, the writing (characters and their motivations) is rather weak.