The positive aspect isn't so much about the PoP's difficulty, as it's about the unique way it handles the difficulty curve: it doesn't really have one.
The intro teaches you the basic moves: jump, wall climb, wall run, rings to extend moves. After that you are quickly given teaching on the additional moves: vine crawling, co-op jumps, and the ceiling crawl. A little later you will unlock the "special moves" in the game which open up the various areas. These moves only work on coloured plates, all work with the same button, and only two of them actually require you to do anything.
The challenge is combining the moves in the correct order with the correct timing. Press the wrong button, or get seriously out of time, and you will fall... I'd like to say to your death, but that would be many Prince of Persias ago. Fall in the new PoP and you will be immediately saved by Elika, your companion, and reset to the last place you could safely stand on.
Despite not having a difficulty curve, each area feels like a new challenge. By using different artistic and acrobatic focuses, the levels don't get repetitive. Each area has a unique look, and the moves to navigate it have a flow that reflects the architecture and layout of the space. You can feel transitions from city to city by the combinations of moves you use to navigate.
The only difficulty comes with self-mastery. As you improve so does your sense of flow, and I found myself becoming further immersed once I could ignore the controls and simply move and run through the world without pause.
Of course, some of this ease of movement is belied by the combat, but that's another topic.