I haven't finished the game yet, but I'll go ahead and post up a short review for people considering the game.
The Good: This game is different. It broaches a subject matter not common in games, the graphics are anime/cel-shaded. (Like Valkyria Chronicles or Borderlands, if you're not sure what that is.) The story is interesting, and the main character is a pretty likable guy. From what I understand, the choices you make in the game drive you towards one of the girls and several different endings, and it's actually similar to the paragon/renegade system used in Mass Effect 2, except there's only one meter for both girls.
The Bad: The puzzle gameplay is frustrating. Honestly, I don't mind hard games, or complicated puzzles, but I'd like enough time to do them. With Catherine, you often have a giant nightmare racing up to smash you, so you end up retrying a lot. Also, you have a limited amount of continues. (but don't worry, you can get more) Then again, when you finally do get it, there's a sense of accomplishment that you won't get from a lot of the way too easy games that are on the market today. Honestly I don't think it's way too hard-just a little. Another simple tip that helped me alot-talk to your fellow sheep. You can move your meter and you learn new strategies for getting up the blocks.
EDIT: Now that I'm farther into the game, I'd like to add a little more detail. There's more to the levels than the blocks slowly falling, or some giant horror chasing you, you'll also have to contend with enemies smacking you around, boss special attacks, (so far I've had getting knocked down, and getting my controls switched to backwards), and trap blocks. Oh, and speaking of trap blocks, here's a tip that I found really useful: You can trigger the spike blocks by running over them quickly, and then you can treat them like normal blocks.
Oh, and I also should add more about the bar part of the gameplay. Basically, you sit and talk to your friends and other bar patrons, and your responses move your karma meter (not really karma I guess, but I can't remember what the game calls it) over to blue or red. I guess you could say hanging out with your friends is reminiscent of Persona 3 and 4, but you don't up your bond with them, but instead get a boost towards one of the girls (and take care because this affects your ending.) Also, your responses to text messages you get from either girl will move your meter. Oh, there's also a tower climbing minigame in the bar.
One thing I'd like to ask the Persona team though, what's up with all the games about climbing towers? Not complaining, just seems a little strange.