Iunno.... Enviromine seemed more inconvenient than evil when I was playing with it in another pack.
Having to drink water was annoying, not any level of difficult.
Insanity from being hurt/darkness was again just annoying, as it messed up your screen and made it even harder to see(although the monster noises were cool).
Temperature was kind of interesting, as needing to keep warm in the snow or cool in the desert makes sense.
Air quality was definitely one of the most annoying things, and would be horrible in a pack like BnB where you already have enough things to worry about while mining.
Physics are cool, never seen em happen in Enviromine apart from sand and gravel, but they are cool(also is added by other mods).
Villager shafts were definitely something I enjoyed, just because it added more to the world(even if the chests inside them were a bit strange).
What it does is add several small annoyances that you have to keep track of, and they quickly become easy to handle....and then you screw up. And it's horrible, and you scream. And mobs exploit your screw up. And you lose your gear. So just like a lot of the rest of BnB.
-Water can be a real problem early on, until you get camel packs and a base. Some biomes don't have good water. Ocean and beach especially. Later on, water and heat have some nice interactions between water cooling heat and heat making you drink a lot more.
-Insanity is a pain. I've gone days while insane and hearing cool noises and making imaginary friends...and then a creeper turns out to be real.
But at least you aren't insane then.
-Temp becomes very difficult mining near lava, making you need a lot more water. Or, while traveling by water or cold biomes, forcing you to stop and warm up.
-Physics has several levels. The basics is that sand/gravel and dirt near water (or in rain) tend to run down hill. It happens when a block updates, like you stepping on a steep hill covered in sand
The other effects can be configured for how much of a span each material group (strong, normal etc.) will hold up blocks. Cobblestone sucks for roofs. Stone is better. Wood planks best. You end up making a lot of pillars and arches. Actually makes for better buildings.
I like enviormine because instead of adding a massive and obvious danger (mobs spawn like crazy, no natural healing), it adds a lot of small factors that add difficulty and slowly chip away at you. They can be countered, but at the cost of time and resources, and paying attention.