I can definitly see the connection between these series, all of them having a connection to WW2, but their universes simply aren't compatible.

Kapten-N said:

I can definitly see the connection between these series, all of them having a connection to WW2, but their universes simply aren't compatible.

They all have WW2 links, and two of them shared a director, IIRC. GuP is the only one that didn't have humanity under siege by aliens or whatever, though.

I think another connection that can be made is that we see the MCs with their big sister or big sister figure.

Kapten-N said:

I can definitly see the connection between these series, all of them having a connection to WW2, but their universes simply aren't compatible.

That's why we have crossovers to bridge the divides, Kapten.