The backstories of other characters were hinted at, presumably to be revealed in Advs 3-5. (Yes, at one point on a stream Minna mentioned Iceland as being the setting for Adv 5!)
Caution: Salt ahead...
Mikkel's backstory in particular leaves so many holes: where did he and Trond meet? did Trond already fire him once? WHAT HAPPENED TO HIS TWIN MICHAEL? What's the deal with his eyesight/processing ability?
Emil's backstory, as mentioned, was foreshadowed and now left dangling. The fire. His parents. His nanny. How the hell they managed to get chocolate in a hamlet in northern Sweden. Also, he has so much development potential going forward, but like Jitter I am sad that he has been almost a non-entity this adventure. He could share dreams with Lalli! He could read some Finnish! He managed a big troll slaying! yes yes go on, and then.... he complained when the bear wouldn't attack him, and he.... um...
Sigrun had the most unexplored potential - her upbringing must have included so much danger and violence, and yet her character development started sliding in Adv. 1 already. Her last piece of genuine development was her angst when she was ill. I don't really get a charge out of her supposed drifting toward a hookup with Mikkel, which I guess was the whole point of her even being on Adv. 2. She was introduced as a zesty character with a taste for Bold Adventure, but she & Mikkel have skipped straight to the companionable cuppa together stage. She had more frisson with Reynir playing Rock, Paper, Scissors, Sheep, Gun. Bah.
Lalli ... who? Oh, right, him. His development has been to accept the utility of an umbrella and show just enough attachment to a toy to advance the plot by a tiny increment.
An adventure is set in Finland - finally, an opportunity to capitalise on the fact that no one speaks the lingo EXCEPT him! What a delicious turnabout! Except that everyone they meet speaks Icelandic and/or Swedish. Who knew that polyglots like Tuuri were actually so numerous in Finland, and all of whom wanted nothing more than to have a companionable cuppa with Mikkel & Sigrun? Lalli goes and hangs out with Emil & Reynir, not talking, even after they meet up with Onni. Again I say, Bah.
Bjarni - the only character other than the crew and HQ staff (and their progenitors) to get an official character intro box. I assume his part in the story was scheduled for the Icelandic arc. Or something.
All the wire in Finland - currently strung along pine trees in the back country. No trolls encountering this to bother Onni anymore? Seagulls perching on it, maybe?
I also thirsted for the knowledge of other survivors and their benefactors elsewhere on the globe, but am content to leave this to us fanfic writers. I don't have massive confidence in Minna's capacity to tell those stories, ya know?
Cinnamon and cardamom and possibly coffee and sugar - what the hey? I am highly skeptical the famed Icelandic greenhouses would be a source for these. Nup.
Kaino Hotakainen. The only major Prologue character to (supposedly) not have some impact on the main story. Why was she introduced (even an official character box) and fleshed out if only to disappear? I really hoped for her to be the kade, such a twist.