I think Mines need to be retouched a tad. They are incredibly easy, as there are only two threats in them until the finale. And of those, only one is a danger as soon as you see it.
That's because the true danger in mines is them generating in such a way that you go down some stairs and then there are no stairs for you to go back up Unless that bug's been fixed.
But yeah, mines are too easy. I'd even go so far as to say that the only really dangerous thing that can happen in them is the terminal and fault-line finale.
Even that's not that bad. Honestly, I farmed the critters who spawned from there for a solid half-hour or so with Rapier + full Light Power armour getup a few versions ago. I haven't gotten there in quite a while, but the endgame stuff probably needs more bits in it. More eldritch stuff is something I approve of and the stuff you can do with the Fungal mutation path seems like its a bound in the right direction. I remember someone[Possibly GlyphGryph?] saying something to the following effect:
There are four main stages to the game:
1: Struggling. You run from problems, scavenge what you can and barely survive.
2: Planning. You organize trips into town for things for specific projects and take one even some of the nastier special zeds head on.
3: Changing. You start changing yourself and your immediate environment by mutations/bionics and by doing stuff like clearing the city you start in or establishing a heavily fortified steel deathmobile.
4: Ascendent. You start changing the game world, like by destroying/spreading fungal blooms or using nuclear weapons on slime pits.
Right now, stage 4 feels the most unfinished because there's an additional layer of interaction which is currently only vaguely there. Presumably as the faction/NPC stuff people are currently working on intensifies, stage 4 will become more fun.