Fireside Lullaby: Nice opener. It really feels like I'm about to be told a story. At first, the instrument choice made me think of a more medieval setting, but then I read the description and it makes sense for the scene you depicted there.
The Underground: This one feels quite futuristic to me and fits the theme quite well. Really like those bandpassed synths at the start. Also really like all the small textures everywhere. Many nice little details to listen for. Really nice use of panning too!
Last Resort: Very dramatic. I can hear how guilt-wracked the brother is in this piece. Given your description, I'm curious which one of the endings this theme's end portrays. It feels like we got the bad ending.
Impressive scoring. My favourite is probably The Underground; but I'm a sucker for synths. I also feel that one really captures the theme well.