A "more of the same" sequel gone somewhat awry. Dishonored 2 is worth playing to the extent that it succeeds at being "more of the same" to the best AAA game ever, but multiple questionable deviations from the formula (many of which seem to indicate the "generic Western AAA mentality" finding its way to Arkane) ensure that it won't be spoken of in the same way that its predecessor was.
First off, a word has to be paid to the mechanical design of Emily. As I've noted before, Dishonored treats height the way Thief treats shadows — high places are your hiding spot, the place you try to hang out while waiting to make your move. However, you can count on guards walking in or near shadows some times — no such luck with high places. Without guards walking near your safe point, you've got no way to strike out at them. Blink solved this, by drastically lengthening Corvo's "reach". If you had an opening, you could blink in, choke, blink out. Emily's Far Reach is no where near as powerful as Corvo's blink; it's a lot less flexible with where you can go, it's not as fast, and it seems like it has less range. As such, you really can't rely on it the same way (Far Reach "down" frequently just isn't available in situations where Corvo would be able to Blink down). To compensate for this, Emily's other powers are more generally useful that Corvo powers that aren't the big three of "Blink, Agility, Dark Vision", but this isn't really a satisfying solution. For one thing, it means that early-game Emily, before she's had the chance to level up a bunch of her powers that aren't in the "staple 3" feels hopelessly gimped, leading to a game with a backwards difficulty curve. For another, it means that Emily's solutions for tricky bits usually boil down to "use the right powers, and waltz on past".
Of course, Dishonored's calling card was its sprawling three-dimensional stage design. Dishonored 2 features plenty of that... eventually. The first two stages are both short little nothings, each consisting of one or two basic stealth scenarios that you're funneled through. The third stage is reasonable, but then the fourth stage... yeah, that's going to get its own paragraph. Three of the assassinations (including the first two "story" ones) are presented as boss fights... why? Did someone at Arkane look at the reception that the bosses in DX:HR got and say "hey, we need some of that in our game!" I just don't get it at all.
Mission 4. Oh god, mission 4. So, to start with, everything about this mission's structure is terrible. It starts with two "mini-scenarios", connected by a rail-car (I suspect it conceals a loading screen). Oh, and the second of these mini-scenarios starts you with your back to a dead end, and guards not three feet in front of you. Already, the game's chief virtue (exploring the huge levels in creative ways) is shot right through the face with this boneheaded decision. Then, the main course, is a network of hallways with no balconies to hide on, so you get to play "try to stay exactly out of the cone of vision in 2D!" in a Pac-Man maze. Wonderful. And, you get to do a big chunk of it while carrying a body, thus making you slower and even more visible. Even better. And did I mention that the main gimmick of the area is that it's a giant maze where the walls of the entire maze move around when you hit switches that are scattered around?!?! Yes, trying to configure the walls of the maze correctly with the switches is exactly as much fun as it sounds. And then, to top it all off, it's a boss-fight assassination.
Seriously, fuck Dishonored 2's fourth mission.
Luckily, after Mission 4, Arkane gets their shit together, and actually delivers the game you want to play (aside from a silly and poorly-considered final boss, that is). Missions 5 through 9 are the roof-crawling atrium-climbing fun you love, with Mission 8 in particular being one of the strongest in the entire series; a well-executed tribute to the classic "mansion" missions from the Thief games. By this point, Emily should be properly tooled-up with the powers she needs to function properly, which even covers for some of her mechanical issues (Domino and Shadow Walk remain just plain stifling to the game's design, though). This second half is strong enough to carry the game, and makes it definitely worth playing. Not strong enough to turn the game into a bona fide classic like it's predecessor, nor enough for the game to get my pick for GotY (that would go to Dark Souls 3), but enough that I do at least recommend the game without reservation.