Primary was one of my earliest fantasy charage... and in many ways it shaped what I was willing to forgive in the genre, rather than how I looked at the genre as a whole.
Primary has a lot of good points... the heroines are interesting, the protagonist's motivations are compelling, and the actual central issues of the overarching story are potentially fascinating. However... it makes the mistake many charage of the type do, of failing to utilize the setting to its fullest extent in most of the paths. Part of this is because Hinana's path is the one where everything is supposed to come together to reveal all the 'truths', and I'm willing to forgive a lot in a story where the protagonist isn't just an average dude.
Unfortunately, the biggest low point of this game is that the protagonist, Rikuo, is not really that smart. He is a skilled mage-knight, and - with work - he manages to keep good grades. However, he is dense about women, more than a little ignorant about issues outside of magic and fighting, and he has a tendency to sort of fall into his relationships with the heroines in their paths (usually because the heroine loses patience with him).
This game contains a few nostalgic archetypes... such as the mild yandere (Lime) and the standard-issue tsundere who is constantly angry (Prim). Not to mention the brocon imouto (Hinana) and the fuwafuwa ojousama (Maria). Their characters, in retrospect, are far more predictable to me than they were at the time I first played this.
While this game could have done with a more focused story, for a fantasy charage it is actually in the upper ranks... it just doesn't satisfy the way something more story-focused would have.