Three more years.
And so it ends, ... but not really. Heart of the Swarm resolves its own internal story, but its hints at StarCraft's deeper, more interesting plot are simply teased along to fit into the years-away Legacy of the Void expansion.
The final cutscene ties this campaign's subplot up nicely, but not nicely enough to wipe away the previous scenes' mistakes: poorly-framed melodrama, uninteresting Zerg-biology technobabble (xenobabble?), a cast of characters lacking any semblance of human relatability, and a mission where two characters literally push energy beams at each other, Dragon Ball Z-style. Back in the StarCraft and Brood War days, the backstory barely intruded into the game at all, and it's hard not to miss that here. The narrative between missions in HotS, more often than not, feels like wasteful filler.
The gameplay, thankfully, is as good as you'd expect from a Wings of Liberty follow-up with a few coats of polish. New Zerg units and abilities are fun to unlock and play around with, and there's a pleasant variety of mission types, including a couple really cool custom scenarios. The final missions are suitably large and satisfying, even if they are still on the "easy" side -- a sense that never really goes away throughout the campaign. Even in small-scale infiltration missions, the game seems to dump way more units on you than you really need, and getting even a handful of the optional unit and Kerrigan upgrades results in the scales being permanently tipped in your favor.
Heart of the Swarm's campaign is also slightly shorter than Wings of Liberty's, but in a sneaky way -- by the Campaign screen numbers, it has 27 missions to its predecessor's 26, but that includes seven micro-sized unit evolution missions (and excludes the three mutually-exclusive mission pairs in WoL). That being said, by the campaign's end, it feels like a pretty adequate length.
Kerrigan's quest introduces a number of cool new StarCraft concepts, and has enough clever mission designs to get by. While the experience as a whole is muddied by sloppy writing and awkward story direction, it's not so bad that a StarCraft fan would be turned away by it.
Better than: Anomaly: Warzone Earth
Not as good as: Sid Meier's Civilization V
Ultimately, not meaningfully better or worse than: StarCraft II: Wings of Liberty
Progress: Finished campaign on Normal.