Well, it seems Spart managed to say almost everything I was going to say about TBG. To sum up what I would've said, this campaign needs a general overhaul
badly. Now, as for the parts that my friend didn't cover...
The characters, aside from those previously established in Aftermath Reboot, never get proper backstories and what info you do get about the new people, including the main protagonist, is... well, it's all thrown at you like birdshot from a shotgun: some hit and stick around (and some are even kinda effective), some glance off and get lost in the background, and the rest miss their mark by a decent margin. And Courtney Aguilar? She comes off as a Mary Sue.
The enemy factions... WHAT?!
The Shivans go from hive minds, massive numbers of fighters, bombers, and ships, and scary weapons to mind-controlled bug people that end up changing sides in a way that seems like it was a plot pulled out of a crappy "what-if" story on fanfiction.net.
The Vasudans... No. You don't send in Serapis and Horus fighters equipped with heavier-than-FS2 armor and spammable missiles in wings hordes like that. And since when did the Vasudans get such a huge xeno-boner for ASMs? This is supposed to be semi-connected to canon FS2, not Blue Planet 2, so why would you pit the player against multiple ships with 2 or even 4 ASM launchers? Oh, and while I'm at it, why would you equip Osirises with HELIOS BOMBS?! Just use Sekhmets. It's post-FS2, so those are fair game. No need to use something that's been around since the Terran-Vasudan War when there's already something better in large quantities.
The Rigelians became the new FS-era Shivans. They can't be touched until someone starts deploying X weapon (either R&D has been developing it from captured tech or it's already in limited use and is now being given to your squadron because Snipes and his SOC friends are "nice" guys) and using them against Y weakness. In this case, it's the Widowmaker missile (speaking of which, why would you hold out on me with those things? I LOVE them!
They're like if you took a Treb, gave it the maneuvering of a Harpoon, and then made it a disruptor weapon as well! It's so OP!). The advice given about using it on Rigelian ships, though... First off, you're right. Don't chase the warships. They're faster than you. However, you got something dead wrong: DO NOT ATTACK RIGELIAN SHIPS FROM HEAD-ON. Approach from side-on, lock on, fire, and wait a bit. 9 times out of 10, that warship will end up a sitting duck without it ever touching you.
Onto the special mechanics...
Point-and-click turret defense with 6 Mjolnirs? ****ing awesome.
Point-and-click turret defense that requires you to juggle blasting incoming capships and defending a fragile Charybdis from bombers and other dickery, the latter of which is so you don't end up with ****-tons of bombers coming in and blasting the turrets and the installation you're guarding? And did I mention that only the first four Atlas targeting hotkeys work, so you end up having to quickly use the vanilla command menu to manually order Atlas 5 and 6 just to use them? Not so much.
Commanding a fleet with the implemented tactical interface is really cool, but when you can only use the first 4 keys to do it, it becomes... frustrating. It was such an obstacle for me that the only ships I managed to save in the final mission were my destroyers and a single corvette, my Chimera-X excluded, and all because I couldn't effectively counter Akhmim's fleet spreading out with a hook.
TL;DR: the 5 and 6 keys don't trigger anything in the Tactical Command Interface.
And one last thing, Herkie: that last message before the final mission (see the link below), considering the dumpster fire that version 1.0.0 of TBG has been... While I understand that it was intended to just be a message to CT and removed later, I'm somewhat glad it stayed in because, to be completely honest, it comes off as you basically just telling your coworker to do all of the work you should've done (but didn't), and then walking out to never return.
https://cdn.discordapp.com/attachments/607738712884772876/695039616021168148/unknown.png (linking here instead of inserting because it's just too big)
I get that you want to be done with this, but no, you can't just dump this all on CT. That's not fair to him, even if you had some kind of agreement during development.
This is an unfinished campaign that deserves better because it could be so much better with more time and effort.
EDIT: I talked with someone with more background on Herkie's situation. I wish I'd known sooner. I admit, I was too harsh.
CT, if you're reading this, DM me if you'd like some help with proofreading and possibly reworking some of the dialogue and story. You don't have to do this alone, and I'm sure I'm not the only one that would like to step in and help.