Ok so I've finally played this campaign. Overall, it has the atmosphere of the original SC Zerg campaign. In line with TOH, terrain and doodad/unit placement for all maps look very professional and polished, specially when compared to the original SC campaigns (which I recently revisited as a result of playing your campaigns and wow... I had a memory of them being much better, but they are actually jokingly simple and dull in many cases).
I like how you mix main objectives with creative challenges, so it's not just a repetitive B&D gameplay but actually one where you must be strategic and boldly chose your targets. And this, despite the limitations of StarEdit (or, maybe, taking advantage of them, which is commendable). Just as in TOH, I've also seen AI workers "freeze" in some missions (Mission 4, Yellow in Mission 5), but at this point I must assume this is an issue of the SC engine itself and not of the AIs. Now, the specific review for each mission.
: The premise is very interesting; you have to destroy a number of Siege Tanks within a given timeframe, and to do so you must coordinate a pincer attack from two opposite locations in the map. I required some micromanagement and careful attack planning early on to ensure both bases grew evenly, but it is a realistic objective and a good start for your campaign.
As a suggestion: I see that one of your defeat conditions is that you lose all of your buildings before Switch 1 (the one that leads to the Drone appearing and moving through the canyon) is set. However, you are required to destroy the Tanks at both
sides of the canyon in order for the Drone to survive. Due to the map design, and since you aren't allowed to build any air units, Nydus canals or research Ventral Sacs, you can't reinforce your forces in the other side, so you must actually maintain your two bases in order to win the mission. Thus, losing either of them should be a defeat condition of its own, even if your other base is on steroids, because there is no way you can win the mission if you can't destroy the Tanks in one side.
: Another B&D mission with some specific objectives that make it more entertaining and compelling. The introduction of Epsilon Squadron and the active use of Science Vessels by the computer is a nice touch to the plot. The Orange Zerg uses the same 'Zerg Campaign Easy' AI script which, as in TOH Mission 1, will actually attempt to build Guardians, with the downside that Guardians are not disabled here for P5. Not sure if this is a desired effect.
About the Garm/Fenris Broods, a minor (and rather cosmetic) suggestion: I didn't remember the broods' names having been directly mentioned by Zerg characters in the original SC or BW storylines, so I checked to see and I could confirm only a brief mention to the "Garm Brood" in The Culling, and just in the mission objectives (Daggoth actually referred to it as "Zasz's Brood", never as Garm). I've always wondered whether the broods were named like that by the Zerg themselves or those were just some sort of 'code names' put by the Terrans to identify them, considering that one wouldn't think of the Zerg using some Norse-mythology names to brand their broods. Maybe it'd be a good idea to have Daggoth & co refer to those as "Zasz's brood", "Nargil's brood", etc. to remove any possible artificiality to it. Nonetheless, this would be merely a cosmetic issue.
: One interesting feature is the Infested Terran character (one which is short-lived and ultimately expendable, ok). Since Zerglings and Hydraliks would be unlikely to manage computers, this is a very accurate and clever approach; in fact, Zerg campaigns in the official SC/BW storyline are characterized by a lack of installation maps, save for The Amerigo one in which you get to use Kerrigan.
This map in particular speaks well of you since it shows the level of detail you put in your work. For example, it's nice to see someone actually taking the care to do something consistent with the installation walls. Most custom maps I've seen just leave the random tileset configurations (heck, even some official SC/BW installation maps, such as The Amerigo or Patriot's Blood, didn't pay enough attention to that). The fact that there's almost no wasted space, the secret Terminal allowing you a Healing Station to help you face the final Tank/Marine ambush and the clear distinction between the research squad (Epsilon) and the attack one (Alpha) further confirm this impression.
: This mission was a tough one to beat due to the continuous DT harassment, but it makes an impressive use of triggered attacks. Precisely, you did get to make it look as if it was the AI that was launching those DT attacks, but they're all triggered by using the hero DT unit.
Dark Swarm proved very useful in this mission against Dragoons and air units, whereas Mutalisks did the day against Reavers. You made sure to make the Protoss strong enough so as to prevent the player from launching early attacks, so it was a must for me to amass a large force before going into the offensive. I got frustrated at some moments since I couldn't reinforce Nargil in any conceivable way without wiping out the Protoss first, but that's the whole point of the mission I think.
As for the Tassadar/Zeratul cutscene, Zeratul is a DT so it feels weird for him to make an appearance but remain invisible to the player's eye. I'd recommend using the 'Turn ON Shared Vision for Player 4' AI script for this until he loads into the Shuttle, then toggle it off, but I don't remember if it was StarEdit-compatible.
: This was one hell of a mission, probably the hardest in the campaign for me, because 1) of the AI scripts at use, 2) the fact that I have to build my own base from scratch and 3) the relatively small room that the map design allows (it's a 128x128 one with three
-initially allied- computer players). I had to restart it two times and save/reload VERY often because I become overwhelmed from all sides very quickly. Basically, I've to go into the offensive while withstanding constant nuking attempts (courtesy of 'Terran 12 - Nuke Town'), Plague+Ensnare combos from Yellow (the hand of 'Protoss 9 - Spell Zerg' can be seen here) and some occasional BCs. Oh, and the lovely Infested Terrans from Yellow. Ironically, the Orange Zerg which use 'Zerg Campaign Difficult' are somewhat kinder
to me at first (though once it goes Muta/Guardian-mad it's nightmarish as well). The Terrans also almost immediately upgrade all techs up to tier 3.
While you are obviously intent on the Terrans and Yellow Zerg using nukes and spellcasters, I'd suggest to balance the AIs by leaving the player some more time to prepare at first, because those two scripts weren't designed to work in tandem. P9 is thought for throwing itself against Protoss (or, at least, a more prepared player), whereas T12 is originally used in a TvT map where the White base is much farther away from the player (which, btw, starts with a stronger army and more resources, while White didn't have any pre-established silos and had to build them first). The only realistic way to win for me without cheating was to take Yellow out first before I ran out of resources at my starting location while holding off White/Orange attacks, then assaulting the Terrans with Guardians. And I didn't manage this in one try. I've seen DK's playtrough of this mission in Youtube and even he, as an experimented and very agressive player, has serious issues at handling this during the first half of the mission. Targeting the Psi Scrambler to have both Yellow and Orange attack the Terrans seems too much of a commodity here.
There is a small "bug" where I can see Yellow ground units being allowed to run freely around the high platforms surrounding the Terran base before the Scrambler is destroyed (probably Orange ones could do this as well, though I haven't seen it due to their base being farther away). This is because OLords will drop them off there before the failsafe triggers you put in place force them to run back to their towns, but I guess they're not intended to do that. Further, it's not frequent but I've seen the Orange Zerg actually bypass this failsafe by entering the Terran base from the other side.
: This mission is clearly inspired by The Invasion of Aiur and Full Circle, but it provides a great improvement to those. Particularly, the quality of terrain and doodad placement of those missions pales in comparison with what you achieved for The Skies Darken.
While in this one you had to manage yourself with care to avoid alerting the Purple and Red AIs ahead of time, the fact that they don't start attacking you right away made this mission easier for me than Divide By Zero (the Warlords and the pre-established Creep Colonies around possible expansions also helped, btw).
I hope I didn't miss anything. I saw you were working on a Protoss campaign to serve as some sort of third installment to this saga of yours, so I hope I may be able to play someday.