Of the four campaigns we got for StarCraft 2 - Wings of Liberty, Heart of the Swarm, Legacy of the Void, and Nova Covert Ops - HotS came out as the weakest for me, the awkward middle child. This stings especially hard because zerg is my favorite race.
So, I had thought of things I personally would’ve changed in the campaign. As I can’t fit them all in a post, here’s a link to the compilation if you’re interested:
Be aware it doesn’t go into anything about the story, just game mechanics I would’ve liked to see implemented.