I've recorded a full playthrough of map 1 and a partial playthrough of map 2, which I will add to this post or as a new reply when it's finished rendering and uploading to my youtube channel. Let me know if you'd rather I keep my video private.
A summary of my feedback is below.
-Marines 'escorting' your character in the beginning (looked cool)
-Simple but effective gameplay twists (from infantry to goliaths to goliaths w/ medic and etc.)
-Contextual clues (vultures lay spider mines as you approach, helpful dialogue before challenging sections)
-Good interplay between characters through dialogue
-I thought my blue marine was expendable at first, because my mission objectives were tucked away in their menu option. Displaying them prominently on-screen before giving the player control of their heroes would help mitigate this issue.
-I have a very difficult time understanding the Scottish/Irish/whatever-he-is guy. Reading his text is next to impossible when you're also trying to focus on gameplay. With voice acting, this likely wouldn't be an issue, but perhaps toning the textual accent down would serve as a band-aid fix.
-I encountered a bug when the infantry exit the goliaths. They all teleported back to the spot where they originally entered the goliaths, and I had to backtrack all the way back while Mint was chased by marines. I imagine this is an issue with your location placement or updating the initial locations.
I actually liked this map a lot more than I thought I would. I've typically not been much of a fan of commando maps or installation maps as I feel like that kind of gameplay doesn't run smoothly in SC:BW, and while there are plenty of moments in this map where I'm battling the engine of the game more than I am the enemies in the map, you managed to blend enough twists into the gameplay experience that I was never stuck doing the same monotonous thing for too long. Even Blizzard's installation maps had this problem, where you'd be forced to backtrack through areas or play chicken with potential infested terran spots or some nonsense of that sort, whereas in this map there's always a feeling of movement as you progress through the layout of the installation and ultimately escape from your captors.
I discuss this topic at length in my video, but your mission briefing is pretty much just a title card. I even spaced out on the objectives (and thus had confusion as to whether or not my blue marine was expendable later on in the map) because I was so focused on explaining the importance of briefings. This is less pertinent to this project and more important to remember when working on your next campaign, since you said before that you're looking to make a more story-driven experience, but I thought I'd point it out so you can keep an ear out for my discussion on this early on in the video.
A big issue with this map, however, is that if you don't know what's coming next, you're basically forced to use trial-and-error rather than skill or understanding of BW's mechanics (unless you play super safe and hold position every other step, which isn't realistic nor is it intended). I understand that it's pretty difficult to create challenging gameplay in this kind of space without keeping the player hopelessly in the dark, and I don't think there's a good solution to this issue - it's really just intrinsic to the engine that you're working with. This kind of map would definitely work better in SC2, and I suppose that's one of the reasons I was frustrated by its execution in BW. I could see your vision for the gameplay and what you were going for, but ultimately the failure to deliver on every intended premise isn't really yours, but the engine's itself.
-Interesting opening, where you move through and gather allies. The units at the player's disposal combine well with the threats that block the player's path to create dynamic gameplay throughout the first portion of the map.
-More dialogue that references the Natiunion (how on earth do you pronounce that) and the clan that the characters are a part of for worldbuilding purposes.
-Some of the dialogue definitely feels more like a tooltip, e.g. the first line of dialogue that includes something to the effect of 'avoid these guys until you feel strong enough to fight them'. Simply stating that a vast enemy force is in 'area X' is enough to dissuade any attempts of heroism, since the player will know not to attack the big enemy base when they have next to no units.
-Lack of gameplay clarity. I'm left wondering whether or not a trigger misfired because I have no minerals, and no indication that I have to find minerals through exploration. A simple dialogue event ("shit, we need to find minerals!" could help the player identify their next objective.
-In the same vein as the above point, perhaps one of the allies you add to your clan could mention the derelict colonial outpost that you can take command of? That will give the player a clear idea on where to go in the early game.
-Lack of characterisation. What is this clan all about? Why do people want to join them? What is their reputation? Knowing the answers to these questions, even partially, could help the player's suspension of disbelief when a bunch of random units sign up for the clan without any discernible reason.
As I mentioned, I only did a partial playthrough of this map, because I failed shortly after finding the minerals and had forgotten to save. I'll come back to this map off-camera and I'll give you more feedback on the end of the mission at a later date.
Gameplay clarity could definitely use some work here. I often don't really know what I'm meant to do or how I'm meant to do it. Some specific points are above, but I definitely think you should use dialogue as a tool to explain more about what is expected of the player (as well as displaying mission objectives onscreen when new objectives are encountered or old objectives are completed). More contextual clues are almost always a good thing, especially when the player is kept in the dark about what's around the next corner.
The later stages of the gameplay (with base building and resource management) seem like they'll be exceptionally challenging due to the low resource count, but almost zero margin for error is not necessarily a good thing when the player is getting their bearings. I'll write in more detail on this when I've played the later stages of the game, but for now, suffice it to say that 720 minerals plus the 240 you get from the group of recruits is almost nothing to field an army with. Maybe it's not as challenging as it looks and you don't even need that many minerals, but it definitely feels less like a classic StarCraft mission and more like a tactical strategy game in this context. I'll decide whether this is a good or bad thing when I've beaten the map.
This map seems like it does its job of acting as a teaser for the more involved macro missions that presumably follow it, though, which makes me anticipate the challenges of future maps even more. When I'm not even done with a map and I'm looking forward to the next one, that's definitely a plus in my book.
Overall, I'm excited to see what else you can come up with, and I'm looking forward to playing the rest of the maps in this campaign, despite its focus on challenging gameplay and my predilection for story-driven experiences. Hopefully, this feedback is useful to you, and you can take something positive away from it to put towards your next project. Let me know if you have any follow-up to my feedback and I'll do my best to respond in a timely manner.
edit: I think you should also add screenshots or other promotional materials to the OP to draw in more downloads. If people want to play custom campaigns, even a cursory glance will whet their appetite. Shots of maps 1-3 generally work in this instance, so long as they don't spoil anything too important.