If not for being announced on the same day as each other, I would not have compared Catherine with School Days. In some ways they are two very different but two remarkably similar games, so the comparison do stick.
On one hand, School Days is a fairly novel game from 6 years ago that took the anime and visual novel media one step closer to each other; much of the first chapter of the game is actual animation. It’s also remarkable for the large number of well-portrayed endings the player can end up with, and a large number of them aren’t exactly what we call “happy” endings. The combination was pretty sensational in an otherwise relatively more-of-the-same genre of bishoujo games with adult content. That is, of course, on top of the slightly different take on the renai motif that is closer to Jersey Shore than the experience of some fantasy animu transfer student who forgot he has a cousin that he is now going to live with, or something.
On the other hand, Catherine, to borrow words from others, is the adult-erotic version of Q*bert. But more specifically, Atlus’s chic-cool Persona team pulls out the stops to make a thriller game based on a man’s instinct to run away from commitment in a relationship? Fielding top seiyuu and animation from Production IG, much of the game take place animated and in a narrative style, like some modern bishoujo games. I think the marketing for the game speaks oodles about why I think Catherine is highly comparable to School Days in terms of using jealousy as a driver, as protagonist Vincent (Kouichi Yamadera…he even looks the role) has to choose between Katherine with a K (Kotono Mitsuishi) or Catherine with a C (Miyuki Sawashiro), while trying to not get killed by either of them, or the mysterious dreams he is having.
Oh, yeah, people die in these games. People meaning possibly you, the protagonist/player. Here’s another bit of similarity for you.
I think it’s safe to say that I am excited about both games coming over and being ported into English. I’m still kind of hung up about buying games with pornographic content, so I’m sitting on the fence for School Days. Isn’t it weird that the game full of high school kids is the one with all the explicit sex? And it isn’t like Vincent doesn’t get any; Catherine’s portrayal of sex is, perhaps, a little more mature and  little more appropriate for a game about a 30-something trying to straighten out his love life? Or maybe it is a little more appropriate for a game being sold to a bunch of 30-something herbivore men? But then again, like myself, the two demographics probably overlap somewhat, despite the entirely opposing approaches to the appeal of realism.