I think a simple, but interesting story should work best. Maybe a prequel where you navigate the space in search of planets to conquer, but not yet going as far as landing onto them - just battling enemy forces, and possibly helping your ally sunfish with the healing beams! I think it's cool to see the events of RotSF from the villains' perspective.
I believe Jinx can answer better about the revenge part, but my impression is that the sunfish are so malevolent that they don't even want to admit they're doing something wrong - from their morality, they are not "conquering" us as species, but exacting "revenge" on us for still being out of their control.
Yeah, but what does it mean? Almost nothing in my games is "random". Same with Kubus, which was one of the reasons I liked him. Did anyone play, Nazi fish and the hard tasks of life? Thats probably the most obvious example. That was autobiographical about him dating some nazi girl who ended up being a real let down, so I was told (there's a lesson there I think). I don't believe people are even capable of "random", it's just not possible. Do you see what I mean? So whats the head supposed to mean? You feel like your being eaten by people with gold teeth and you have to explode them? Enlighten me, honestly I think all views are valid at least to the viewer.