Loving the game, currently playing on easy (no bonuses/maluses for AI) and it's challenging in a way I rarely experience in 4X games. In my current game as the environmentalists I've been in a brutal war with the dynasts for a long time, fighting mainly over one city. The AI is very competent, landing naval invasions on my flanks and rear, decimating me with aircraft, etc. Technology choices seem to really matter instead of simply being leading in tech or not. I was terrified when I had little army tech researched and they declared war on me with aircraft and tanks, and have been struggling to hold on despite seemingly losing the war of attrition, when normally I tend to get bored while losing this kind of game. Currently I'm working on getting nuclear weapons, and hope that will turn the tide of the war.
In terms of wildlife, I didn't realize the wildlife was docile, and the environmentalist -% aggressiveness seems unfortunately not very useful, as I'm not even far into the game and all the hives seem to be gone with no new wildlife popping up, though maybe I just haven't hit the pollution point where that happens. The game definitely lacks the personality of SMAC, which is a shame but I guess wouldn't have been replicable.
Overall I like it a lot and recommend it, though for hardcore players of SMAC spending too much time comparing and contrasting the two will probably hamper enjoyment.