There are many ways a video game can be difficult. It can force you to succeed with minimal room for error, like Celeste or Katana Zero. It can give you some room for error, but if you screw up too much, you end up failing, like Dark Souls.
Xcom 2 is different. You can get 3/4 soldiers killed on a mission and you'll be mostly fine. Heck, the tutorial first mission has you get 3/4 soldiers killed. You can screw up during combat without everyone immediatly dying (unlike something like Fire Emblem). You can make suboptimal plays on the world map and won't get a game over anytime soon. In fact, it's incrdibly difficult to get a game over in this game. You either have to really screw up multiple missions in a row, basically choose to ignore the Avatar Project, or fail one of very few critical mission.
But your mistakes pile up. And if you make too many mistakes, your soldiers die. And if too many of your soldiers die, you can't defend the avenger when a UFO hunts it down. Or you neglect some upgrade path and feel yourself becoming more and more powerless.
I've never played a game as difficult as Xcom 2 with as much room for error, and I love it for that.

This game is absolutely fantastic, and i've sunk so many hours into it in such a short amount of time.
If you take everything that made the original XCOM and its predecessors so great and refined what was there, you get XCOM 2. It has a challenging but fair battle system that may throw off new players, but still have some challenge for veterans of the XCOM series. Most of the soldiers have been changed, but its for the better, considering some felt under-powered, and some felt too strong for their own good. As always, they can be customized to your liking, but that's been added to weapons as well. Tough and rewarding, XCOM 2 is a fantastic experience that will keep you engaged for a long time. I've sunk almost 30 hours into this game, and there's still alot that I haven't done.

XCOM 2's combat is just as solid as before, but its sloppy and irritating tutorials that persist across the game's clunkier-than-ever grand strategy elements make it feel like a step or two back from its predecessor.

XCOM 2 is also aesthetically uninteresting - Gone is the campy layer of that classic, retro-futuristic UFO science fiction flavor in the game's most prominent alien footsoldiers, and in place are large swaths of generic Gamer-PC looking foes that may as well not be alien at all.

The sum of XCOM 2's parts is an unfocused mess, carried by elements that don't feel dramatically improved upon from it's predecessor. The big question: Why play XCOM 2 over XCOM 1?

I have an extreme love/hate relationship with this game. On one hand I enjoy the challenging, tactical gameplay and love both the perma-death and character creator which adds a nice personal touch, but the RNG is notorious for a reason and missing your attacks point-blank with a 90% accuracy rate is only funny so many times before it just becomes annoying and obnoxious, plus as others have already mentioned the difficulty spikes in missions and endgame is ridiculous as well.

Overall still a great game and a lot of fun if you're a masochist, but too many annoying mechanics that keep it from being the masterpiece it could've been. Still the best XCOM game though as far as I am concerned.

Like XCOM: Enemy Unknown, the first 10 hours of XCOM 2 were brutal. I had barely anything to work with, a constant barrage of problems to solve, and soldiers that died left and right. It was a real power struggle, and one that made me frustrated quite consistently. Unlike EU though, once I was over that hurdle, it wasn't entirely a walk in the park from then on out. Still easier, sure, but it maintained a stable level of challenge that didn't extinguish even going into the finale.

XCOM 2 continues the series tradition of balancing that fine line between accessibility and complexity, while adding plenty more mechanics in to further deepen strategy. New tools have been brought in to alleviate some of Enemy Unknown's problems. One big example of this is through methods of scanning ahead for targets, which fixes the major issue of feeling like you've screwed yourself because you moved one of your units slightly too early. There's also more depth to each character, with various attachments to lightly buff their weapons, installable upgrades, and more.

Speaking on characters, the personality that made Enemy Unknown as good as it is has received far more attention with tons more ways to customize your character. You can even write backstories for them if you're really into it. Combined with what I hear is more interactivity between units in War of the Chosen, and it's a storyteller's dream. I made many of my friends in the game and it was fun seeing some survive, while others saw their stories brought to a sad end (including one on the final mission).

All of this is combined with some heavily increased variety which was sorely needed. Missions are much more diverse (I can count the amount of repeated missions I ran on one hand), enemies are more numerous and unique both in design and in challenges they present, and surprises are far more plentiful.

These aren't even touching on some of the minor improvements. You can load a past save while the enemy is still taking their turn (thank god), more diverse equipment can be researched, the base building mechanics have been tightened up, the geoscape is far more interesting. The list goes on.

The only issue I can genuinely hold against this game is the time some turns and actions can take. It isn't obnoxious, but I've had moments where enemy turns can feel like they take way longer than they need to, even with some unnecessary pauses. I can forgive it given everything the game does right, and a mod can easily fix it, but it's still an issue.

Even with that, I don't see any reason to give this game any lower than a 10, and I didn't even play the beloved WotC expansion yet. This is a masterpiece that builds upon the first game's foundations while adding its own flavor on previous mechanics, helping it feel refreshing even after recently playing XCOM EU. It's easy to see why the game has received such endless praise, and it's one I very much plan to revisit down the line with WotC enabled this time. If you're on the fence about turn-based games or simply want one of the best experiences in the genre, this is it.