For instance, do you get to upgrade/customize this mansion? How does one actually acquire their harem? Do you just get prompts as you progress the story or will you have to ferret out side-quests and events? There also seems to be some kind of relationship system with harem members.
Honestly I'd like to increase the requirements for RPGs, given they make up the bulk of the threads and experience can vary so widely. Answering questions like "How hard is it to progress questlines, are many of them broken? Is the game linear? Or how much time should one expect to put into grinding" perhaps even requiring them to give an idea what kind of progression the player goes through, is it only party-centric or are they building an estate/town/kingdom?
Going one-by-one:
-Upgrade? Limited. Customize? Yes.
-Acquired early in the story, less that 15 minutes in. Basically, mansion = harem.
-Sidequests are generally found by exploring. Everything is generally non-linear with certain barriers created by certain required story events that happen automatically over time.
-You gain various bonuses by building relationships with your harem girls (and there are a couple of guys who are more there for facility reasons - like a blacksmith). The bonuses vary quite a bit, from stat boosts to additional sex scenes.
-Questlines vary by quest. That goes without saying for
any RPG out there, so that's a very moot point (so don't expand "standards" to include this). As far as this game goes, each quest is stand-alone but certain quests require you to finish others before you can start a new one. Also, potential for spoilers so again, don't expand "standards" to include this.
-Mostly-nonlinear. See above.
-100% subjective for this game, and I could say it's 100% subjective for all RPGs as well (again, don't expand "standards" to include this). In this game, you can do as little or as much as you want because you're going to get into fights regardless and each quest has level recommendations. There's also a limit to how much grinding you can do because monsters despawn until the next day.
-It's mostly just a selfish freewheeling protagonist trying to add girls to his harem. He does pretty much whatever he wants, invest in what he wants, and so-forth. I'd rather NOT say because that can be considered spoiler territory, and therefore, I'd also say it's better not to include this in the "standards" for a thread.
As for that last bit, people write the bare minimum for RPGs because they are a very mixed bag on what to include and what not to include. We're not here to write a frikken walkthrough to introduce the game. RPGs also have things like spoilers, long stories, and a lot of similar-yet-different mechanics that most gamers are familiar with because most games include RPG mechanics.