This post was edited on August 10, 2014, for better spacing and ease of reading.
The Rebellion missions in Wings of Liberty were fairly straightforward. Raynor starts it off by hijacking Dominion trains to capture some secret cargo, which happens to be a Confederate computerized adjutant. He then has to get its classified information decrypted, and fights the criminal doing the job for him when said criminal tries to sell it off to the Dominion.
After that, the third mission involves capturing the prototype Odin walker, while the final mission has you unleash it on Korhal as a distraction while Raynor’s forces upload that secret information to the media broadcast centres. That broadcast contained a recording that discredited Arcturus Mengsk severely.
The secret mission “Piercing the Shroud” is technically also a Rebellion mission, but it is not actually related to the others. While there were some problems in how the missions played out, the general principle behind them was very good.
To start with, there was the fact that the missions demonstrated what Raynor’s Raiders were trying to do in their revolution. Their goal, essentially, was to bring down Arcturus Mengsk and the corrupt government of the Dominion. Most of the other missions in the game ignore that objective and go off on tangents, such as the levels where Raynor gives Tosh some support. However, the Rebellion missions show Raynor taking action to move towards his final goal.
Incidentally, it should also be noted that the original StarCraft is tied in very effectively for this series of missions. The Confederate adjutant in the first two missions dated back to the invasion of Tarsonis. The broadcast used against Arcturus to great effect was two separate recordings of his words in the original Terran campaign of the first StarCraft. First, there was this full recording at the end of the eighth mission:
Duke: This is Duke. The emitters are secured and on-line.
Kerrigan: Who authorized the use of Psi-Emitters?
Arcturus Mengsk: I did, lieutenant.
Kerrigan: What? The Confederates on Antiga were bad enough, but now you’re going to use the Zerg against an entire planet? This is insane.
Jim Raynor: She’s right, man. Think this through.
Arcturus Mengsk: I have thought it through. Believe me. You all have your orders. Carry them out.
Then, in the last mission briefing, there was a partial recording of Arcturus’ words, in particular the bolded part. Note that the adjutant here is not the same as the one later discovered by Raynor in Wings of Liberty:
Jim Raynor: I can’t believe he actually left her down there. I’m gone, and you better come with me. There’s no telling who Arcturus will screw over next.
Adjutant: Receiving incoming transmission…
Arcturus Mengsk: Gentlemen, you’ve done very well, but remember that we’ve still got a job to do. The seeds of a new Empire have been sown, and if we hope to reap…
Jim Raynor: Aw, to hell with you!
Arcturus Mengsk: You’re making a terrible mistake. Don’t even think to cross me. I’ve sacrificed too much to let this fall apart.
Jim Raynor: You mean like you sacrificed Kerrigan?
Arcturus Mengsk: You’ll regret that. You don’t seem to realize my situation here. I will not be stopped. Not by you, or the Confederates, or the Protoss, or anyone. I will rule this sector or see it burnt to ashes around me! If you try to get in my way…
Adjutant: The fleet is prepped and ready, Commander. Awaiting orders.
Jim Raynor: (to the Magistrate) The hell with him. We’re gone.
Taken together, the two recordings make it clear that not only did Arcturus cause the destruction of Tarsonis by drawing the Zerg there, but also that he was driven solely by desire for power. Given that Arcturus’ rule is founded on the idea that he is serving the people, this would be extremely embarrassing for him. The fact that he was responsible for the extermination of the people on Tarsonis would likewise damage his reputation severely.
It should also be noted that the missions themselves were not directed at fighting the Dominion head-on and defeating armies with Raynor’s tiny rebellion. Instead, they worked through somewhat more subtle means than brute force.
For instance, the last main mission, “Media Blitz”, culminated in a serious scandal for the Dominion, not some military takeover of the government. Raynor used the Dominion media against Arcturus, not brute force. The execution of the mission was unfortunate, as you can actively wipe out the Dominion bases with the Odin, but that is not directly related to the principle behind the mission.
It is a more realistic approach for Raynor to take when compared to to the tactics used throughout other missions in the campaign, like the open assault on the heavily defended New Folsom prison. Assaulting Korhal would only get Raynor’s Raiders killed, whereas humiliating Arcturus could potentially cause an uprising that would remove him from power.
It is unfortunate that all of the damage caused was effectively ignored in Heart of the Swarm, but the background behind the missions was impressive. They offered a practical way to damage the grip Arcturus held on the people, and the missions had Raynor working towards his goal of deposing Arcturus, unlike a substantial number of other levels in the game. They even referred to the original game in an easy-to-understand fashion with those recordings that would avoid confusing those who had not played it while still giving the reference a significant role.
If Blizzard had invested a similar degree of time and effort into the other branches of the campaign, it would probably have been much better off for it.