The battlefield itself remains familiar to XCOM vets for better or for worse. You and your enemy take turns moving a squad of soldiers through an isometric grid, balancing offensive and defensive abilities against the odds of success and failure. The new design favors iterative improvement over system revamp - a smart decision, even if maintaining its predecessor's core design didn't leave much room for significant advancement.
XCOM 2 brings five classes into the fray, each an evolution of Enemy Unknown's. You've got Grenadier (Heavy), Specialist (Assault), Sharpshooter (Sniper), Ranger (Support), and Psi Operative, which is now a stand-alone class as opposed to a class extension. Skirmishes and encounters have a few new twists, but little that feels substantial beyond an initial "ooh, shiny!" appeal. Take the new hacking system. Certain objects can sometimes be hacked to complete objectives, stun enemies, or even temporarily control certain enemy units. There's no real minigame for it, just the small choice of which reward you're gunning for and what consequences you're willing to risk in the attempt. While packaged a fun new interface, the process ultimately feels anemic, as if its main purpose is simply to mix things up a bit between the shooting bits. And that's fine.
The development team did a lot of work to fix and improve procedural generation for the maps your team will visit (and subsequently destroy) on these missions. Out with random smatterings of cover, and in with a smarter design that makes sure you've got tactical placement options where and when you need them. The effect certainly makes locations feel more natural-gone are the days of full-cover pylons at the edge of a forest-but don't expect a fundamental shift how you interact with the environment.
Combat itself is still tactical and rewarding, somehow producing hours upon hours of genuine fun through an assembly line of similar encounters. You'll position your troops, weigh the risks of moving or shooting, knock out the baddies, and go home to bask in the advancement of your surviving soldiers. The dead (and the hours that went into training them) will be mourned, but quickly replaced with fresh recruits ready to take up the mantle and drop back into battle. The cycle is as great as it ever was, but the design team's smart adherence to form seems to have brought along more than a few unwanted stragglers from the olden days.
As inconceivable as it may seem, the camera is still as ornery, unpredictable, and buggy as ever. It still decides whom to follow and how to follow them, often regardless of what's actually happening on the battlefield. During most missions, I experienced multiple occasions in which the camera would take a breather in the middle of combat, choosing a single soldier to sit on while the outcomes of enemy actions were decided off screen. In a few extreme cases, the camera never got up again, asking me to decide between a seemingly perpetual inspection of my squad leader's hairdo and loading an old save to keep playing.
Aside from camera hijinks, the game suffers from a few oversights that can mar an otherwise smooth and engaging experience. For instance, certain story missions require a player to either fail or pass all objectives before triggering an official end. If you're losing, it's a massive frustration to know that no matter how you play for the next twenty minutes, you're eventually going to fail the match and be forced to restart. In similar games, this is where you'd restart a mission manually, but as XCOM 2 doesn't provide the option, nothing other than a protracted loss (or strategic pre-encounter save) will allow you to continue.
The game will also sometimes lag after gunshots, explosions, or actions, leaving a soldier's interface open for about three to five seconds when the game has moved on to an off-camera unit. That may not sound like much, but it's enough time for you to click a command for the wrong soldier. Best-case scenario, nothing happens, and you realize your mistake. Worst-case scenario, you waste a turn triggering an action meant for the next soldier in rotation. Weirdest-case scenario, you trigger a second action from the same soldier that you didn't have remaining action points for. Pulling off two sniper shots in one turn is great for killing sectoids, but not so great for feeling like you've earned it.
Those squabbles aside, XCOM 2 is a fantastic accomplishment, and series fans will be happy to hear it's better than Enemy Unknown in pretty much every conceivable way. The few frustrations that do exist are primarily technical, and while the camera's unlikely to see a reboot anytime soon, the rest could probably be fixed with patches in the future. Furthermore, as you don't need to have played XCOM to enjoy XCOM 2, so there's little to no barrier to entry for new players beyond its narrow PC-exclusive release. (Sorry Xbox, PlayStation, and iPhone!). All in all, XCOM 2 is a great choice for both long-time fans and tactical action enthusiasts looking to jump into the series for the first time.
Bottom Line: XCOM 2 improves on its predecessor in almost every way, and proudly stands as one of the most deeply satisfying action-strategy games currently available.
Recommendation: Whether you're new to the series or clamoring to dive back in, XCOM 2 is a complex and challenging game worthy of a day-one purchase.