>>580Baldr Sky:
A vn about mechs.
I'm going to take a stab in the dark and say that it is more competitive than survival (ie. some mech competition rather than a kill or be killed situation.)
MC somehow is a neutral party; picking a team/faction to align with.
This VN is wider than it is deep. Although there is a main route, it is not a "true" route.
Aiyoku no Eustia:
There is a good amount of emphasis on the girl with wings. I would normally see this as a symbolic thing, but given the medium, I will assume that it is a literal interpretation.
The same is true about the crumbling city.
Connecting these two, I would say that the story is about a religious empire that is somehow flawed and/or corrupt.
MC must choose whether or not to align with the rebels or the empire.
There was something about a princess, so I would guess that you would end up taking her route if you side with the empire.
Sharin no Kuni, Himawari no Shōjo
https://www.youtube.com/watch?v=k6RHKVQC4akI just finished this the other day. I think it is impossible to guess what it is about just by looking at the OP