I like badder bosses, swarm int and runes quite a bit. Hostile champs keeps you on your toes and pulls enough random bullshit that it's a constant challenge paired with the above.
I don't really like barren land, I find removing mechanics like plants unfun.
As a Huntress player who relies on range and grass cover, Darkness and Barren are the 2 I dislike the most (though I could deal with them in a low chal run). FiMA can be rough but it teaches you a lot about avoiding damage, similar for Pharma where healing is at a premium especially time-wise.