I think the game establishes a really nice atmosphere at the start, the cages full of decaying bodies and all the people suffering from the spores scattered around struggling. Though the confronting atmosphere gets broken once they decided to copy and paste the people all over the game with action loops and zero interactivity. The scene with the lady screaming "They took my children" is probably the most memorable part of the whole game.
But I feel that the game rapidly degrades as you suddenly find yourself becoming a faceless nameless grunt taking orders from random radio people.
The whole hunt for Gould was quite interesting, there was a sense of vulnerability as you are on the run and still new to the game. Also Gould represented a piece of the puzzle that would help explain the situation you are in. But I feel like after all the effort Gould was a complete let down, the revelation that "We're getting our asses kicked but squid," and "I can't do this man," suddenly shoves the focus of the entire early part of the game into the background and sets you on a completely different path.
At this point you've got a good handle on the nanosuit and human targets should have completely stopped being a threat, the game just did not seemed to be designed in a way that provides difficulty for users of stealth mode. There aren't enemies positioned to get in the way of you advancing into good positions and the extremely lackluster AI makes watching enemies search for you a complete joke, especially if you have a silenced weapon on elevated ground.
The entire section with Barclay where you work with soldiers to fight aliens is also quite bland, it's just a series of getting to a location, jumping on a turret, blasting aliens who advance towards you all from the same direction, rince, repeat. The occasional Ceph ship battle is kind of interesting as you hop from cover to cover retrieving weapons to deal with the threat. Alien Brutes are also quite lacking in threat once you work out you can just strafe around them with a shotgun or take them out quickly with a K-Volt. The big walkers are simply tedious to deal with, not entirely difficult but very time consuming. Overall I think I would have liked to see more enemy variety or at least better tactics used and less generic level designs. That's not to say the levels themselves aren't beautiful but the playing areas you end up in become quite repetitive.
The game does however redeem itself a bit at the end when you mount your assault in the central alien structure, the ability to fall to your death felt a bit unnecessary however the number of aliens and their placement as well as the slightly reduced availability for cover and overall layout provided quite a lot more fun in terms of challenge. I also would have much preferred more opportunities to deal with the cloaked Ceph that appear at the end of the game, it seems such a waste for them to have restricted such an interesting enemy to a single encounter.
Overall I think that the game is decent, moderately enjoyable single player, multiplayer is quite fun if not a bit limited compared to other shooters. However the game had a lot of potential to be much better that it didn't seem to meet. The single player feels schizophrenic and unfinished, being able to use a microscope in the game as well as phones that don't work seem like awful wastes of time when there's a bunch of copy and pasted NPCs that cannot be interacted with. Having the hold down the throw button to do a big throw also severely limits the fun you can have with explosives (Even with power throw it doesn't go very far). Though I highly recommend everyone to try powerkicking a car as a weapon at least once, this is especially fun against brutes.