Watching other people do it doesn't really help, it just gives you an idea on how to do it. It depends on how good you are, like on LBP I got platinum in about 2 weeks of playing, so I think im quite good at it. And on LBP2, Ive aced about 3/4 of the levels so far. Also, on my first playthrough of the whole game, I got 83% of the prize bubbles. But back to the point just watching some one do it only gives you an idea on what to do. You need to be some what good at the game. Yes, this does help me as well.