Guild Wars 2 had that design philosophy: "Either the Charr have no breasts, or they have six breasts." They're catfolk who give birth to litters. They went with "none", but you can still generally tell male from female ones, they had gender dimorphism. The Skritt, ratfolk, you couldn't tell the genders apart very easily at all, but I think there was some minor difference, just one not immediately visible.

They also had a plantfolk species that did have breasts on its "women"... But it is an ungendered species that cannot reproduce. Some look like human females specifically because the sentient plant-crafting source was helped/saved by humans, and thought that its feelers looking like humans would help integrate its seedlings to integrate into their society.