Graveyard Keeper is a really good game (the DLCs vary in quality, but still worth playing imho). I liked the dark humor and err, questionable morality. The NPCs are terrible people and I loved it. It was quite refreshing after playing mostly wholesome games!

I'm with you on the time investment. Getting started in it is brutal, with most of what you can sell being near worthless at first (and, if I remember well, prices drop when you sell too much of something? It's been a while). It takes time and effort to get yourself established, which makes it very satisfying!

(I also ended up drowning in stuff. Once you get the collection of resources going, it doesn't stop.)