2.5 dimensional means they are more developed than a 2 dimensional character but not quite 3 dimensional. a child character or childlike character is better if they are not done for the sex appeal. this is why i usually cover my childlke characters in modest fitting outfits and try to cover up skin in some way with something either cute or professional.
Ah I see.
I do also think that child characters (who are actually children and not just moe) are better, but I still don't like child characters anyways. That doesn't really have anything to do with the concept, but more to do with the fact that I have yet to come across someone who writes them well. It doesn't really make much difference it they're presented modestly, though at the very least I don't have to come away from an encounter with such a character feeling like I need to bleach my brain lol.