I've completed Heavy Rain twice and am still only 49% through as each action changes the course of the game. It's like a very intense film that you control and the script is brilliant.
The tutorial is the prologue and helps you get to grips with how to control the game.
I bought this game for 40GBP when it first came out. I went to play the game again last night and was waiting an hour for it to update, once it did I had the MOVE edition for FREE! So, if you don't mind waiting an hour, save yourself a bit of money and buy the original instead of the MOVE as it now comes free... I love the PS3. XBox would never give you anything for free! :)