With all the hype and scaremongering about this trophy, I had a USB stick prepared and everything, only to realise just how easy it is.
I can personally confirm, this is how you obtain the trophy:
Play on any difficulty you want.
Don't die during the life upgrade sections.
You CAN fall during the final chase with the Dark Prince.
If you die at any point, you CAN rewind time.
If you get to the retry screen, or if you die before that, just hit the XMB and quit game and load your last save and play as normal.
That's literally all you have to do, this was way easier than Warrior Within's similar trophy, not harder.