I've been playing Totori, so my opinions are based on that. Can't speak for the other entries myself. I'm not too far in, but so far there really hasn't been any over sexualization, besides the standard "girl armor" and fanservice shots from behind during attack animations. And it certainly isn't fully female cast, I think 3 of the playable characters are male. From what I have seen, it is more about being cute and less about being sexual, but that could change.
Gameplay wise, it is pretty unique. General premise best I can describe is that everything you do uses "time", such as battling, gathering, crafting, traveling or resting. Goal is to progress the story and complete quests without "running out of time". Ironically, walking around a town or area, or putting the game down and actually wasting time is the only thing that doesn't use in game "time". Battle system is simple and turn based, with mobs being visible and generally avoidable if you want to avoid them. A big focus is the crafting system, or alchemy, where you go out and gather items from gather points or killing monsters, and combine them to make the things required for quests as well as items and equipment like healing potions. Things you gather have varying grade, and as expected using better materials nets better items, which get you better quest rewards. Your main character actually sucks at combat, so these items are vital to survive.
Man, I realized now why I couldn't find many good impressions of the game before I bought it, its pretty tough to explain. I definitely did not do it justice. I've found the cycle of explore, gather, craft repeat to be fun and satisfying, but if you are mostly about combat in a turn based RPG that isn't really where this game is best. Gah, maybe someone else will do a better job helping you than I just did.
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