I'll just kind of hit the bullet points for the IP hate.
-As Segata mentioned, the level of pretention seeping out of every bit of it is nauseating as hell. I don't need the director to have himself rendered into the game, just to tell me how great his game is. This is the very definition of being up one's own ass.
-The QTE's make absolutely no sense from a control standpoint. Look at the ones in Shenmue; they follow a certain logic. If Ryo is going to throw a punch in a QTE, chances are the button you have to press will be the same one you'd hit to punch during the free battle mode.
In IP, this logic is nowhere to be found. QTE's are relegated entirely to thumbstick control, and basically just go in random patterns while a video plays. It's not an interactive cinema scene, as you'd find in Shenmue; it's just a cutscene where you have to fling the thumbsticks around for no reason. It's lazy and dumb.
-The stealth bits are just flat-out awful. Truly the worst stealth sequences I've ever played. I don't remember the specifics, I just remember for the first time feeling like I was absolutely wasting my life playing this crappy videogame.
-There's almost no aesthetic congruity throughout the entire thing. It'll first try to present itself as some kind of mature thriller, then it'll have an idiotic sequence where two characters are literally kung fu fighting in a sparring ring, then it'll have giant bugs chasing the main character through an office building, then it'll have something involving Mayan prophecies in a museum, then it'll have ancient energy beings flying around Matrix-style in another kung fu fight. It's about as idiotically random as can be.
-Necrophelia.
You know, I think the worst thing about it is that it has certain elements that legitimately could have been great.
The initial concept of the main character being possessed into killing someone, and later finding out that it was done in an insanely precise way, severing each individual artery connecting the heart to the rest of the body...
That's really cool. The idea of it tying in to the method of Mayan sacrifice or something makes it seem even cooler.
And I do remember a couple of sequences that felt like they should have been more affecting to me; one involved the main character visiting some old woman in her apartment on a snowy day, the other involved him searching a library for something or another. Something about those two instances just struck me as having great potential for atmosphere. But they ultimately failed, because the rest of the game was just so damn poor. The context killed them both entirely.
It's just a truly bad game. I don't say that often at all, because most games have at least some merit to them. But IP is just poorly-made trash. It starts out okay , but very, very quickly abandons anything it could have done right.