Timeline differences, other than choosing whether Fergus or Wyatt lives?
Fergus Timeline you get the ability to bypass electronic locks via hotwiring.
Wyatt Timeline you get the ability to bypass mechanical locks with lockpicks.
Though I personally don't think this makes a lot of sense . . . While you can justify the Fergus Timeline as BJ simply never acquiring lockpicks, as Wyatt is the one to give them to BJ in the Wyatt Timeline . . . There's literally no reason that BJ shouldn't be able to hot wire things in the Wyatt Timeline. He doesn't require any special tools or anything. Just his knife and his hands. (And he always has a knife and his hands.)
In the Fergus Timeline, you find Health Upgrades. These permanently increase your Maximum Health. (Up to 200.)
In the Wyatt Timeline, you find Armor Upgrades. These permanently increase the value of Armor Pickups. (When you get them all, Armor Pickups are worth double what they were when you didn't have any upgrades.)
In the Fergus Timeline, one of the members of the Resistance is an insane woman named Tekla that's mostly obsessed with statistics. She's a little bit of a bitch. (I didn't like her at first, but she grew on me.)
In the Wyatt Timeline, instead of Tekla, you meet a guy named J that mostly just plays the guitar and does drugs. He's apparently supposed to be Jimi Hendrix, and his face is really fucked up. (He hides an assload of scar tissue behind a bandanna.)
Honestly . . . While he's usually pretty nice, I prefer Tekla and what goes down with her over the stuff with J. I also think the Health Upgrades are more useful than the Armor Upgrades.
So yeah, first run through? I'd strongly recommend you save Fergus and let Wyatt die.
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And yeah . . . Stalin is the only leader explicitly named in a newspaper clipping.
Hitler gets mentioned once by a guard that says, "Heil Hitler!"
In the same scene, you learn that one of the Robot Dogs is named Blondie.
Beyond that, as mentioned, they only ever refer to world leaders by their title.
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Also, even though he'll probably live through the power of sheer bullshit, I'd actually prefer it if BJ died at the end.
Deathshead's arm, head, and part of his torso was fucking obliterated by that grenade.
The way he was holding it, the grenade was closer to BJ's head and torso when it went off than it was Deathshead's head and torso. (Plus, BJ's guts were totally spilling out.)