I take back what I said earlier about this game not having any tough and obscure exploration puzzles to crack compared to the first one.
There are a few tricky ones that require you to pay attention, manually search through your log (not quest log - conversation and research log), and go back to older places you've been. Your crew helps you out a little by telling you they cracked some old puzzle, like "Hmm that shadow of a burning moon those creatures told us about, there was a volcanic moon not far from there."
But this isn't a quest, it's just something off-handedly mentioned, and you have to go and check it out yourself.
Right now I'm close to the ending and I can end the game any time I want, or do one final task for the Talonian before going back to my own universe. I wager there's an optional better ending if you do it.
This quest is the kind of obscure stuff I crave. Just activating the Talonian's memories requires you to give him sufficient fragments, which you can find scattered across the map, usually as a reward for solving a side quest or exploring a particularly involved planetary exploration.
Now I'm supposed to find some remnant of Arkadians, who are a vanished race, and the only hint I got is an ancient star map pointing me to a system with a signal tower that can open wormholes to certain locations that can be chosen by binary code.
The important thing is that one entry is missing its code, and you have to reconstruct it by analyzing the binary codes of the others, finding a pattern, and figuring it out.
I had to use a binary to decimal tool on the internet to figure this one out. Really cool.
Some of the side quests are pretty cryptic and/or take a lot of legwork too and you pretty much have to do all of them to even receive that final optional quest.
Loving this shit.