I'm a sucker for realism in my stories. I would love for them to have traits that are similar to one another; but as someone who had a lot of siblings, I'll tell you right now that siblings don't look super similar all the time. I think it should be subtle, eyes, skin tone obviously, but a few differences in hair (or they can dye their hair) and different facial features are fine. Obviously body types can vary wildly.
But I definitely prefer when you can look at one and say "ya, ya I can see it" especially if you add an LI that's either not a family member, or is more distantly related and it's obvious there's a difference between that character and the other LIs.
They definitely should yeah, even if it's not going for the whole twin thing. I know some families can have a blonde and a brown haired sibling but, let's be real, that aint what people are looking for.
They should look vaguely similar-ish. On the other hand, I know real life families where brothers and sisters do not really resemble each other - one takes after the dad and the other takes after the mom.
Well, siblings in real life do not look very much alike most of the times. It's more the case that when they do, people notice and mention it as something funny and curious.
Unless they are radically different phenotypes, it's fine with me.
I find it more to be the case that sons look quite like their fathers, and daughters look like their moms, than that siblings look alike.
Absolutely. It's a part of the kink, imho. If there is no likeness, it goes straight into the "step-family" category, which is meah to begin with (there is no taboo).
Siblings often do not really look similar at all. More often they resemble a parent or grandparent more than each other.
With more variety the probability of one or more of the characters meeting my personal taste increases, so I prefer them to be different.
Yeah, games like Radiant are a bit weird. All three sisters have radically different hair colors. I suppose they could dye their hair, but I doubt that was the intended reason.
I'm developing a game and that's one of my main issues. I try to add qualities into each character within the same blood-line, but dealing with some of the models is difficult. Something I didn't know was how assets can break when applied or altered by other setting, meshes and shaders. It's a real pain in the butt to develop characters that can be used in all environments. It's a game of compromises.