This is the exact problem I have with the grandmaster galaxy in super mario galaxy 2. I die a bazillion times on the final 3 parts of the level, and I want to retry that part of the level. But then, the game sends me back to the beginning of the level. THANK YOU GAME, BUT I'VE ALREADY PROVEN I CAN BEAT THIS PART A THOUSAND TIMES. I just want to retry the part where I died, not the entire level. Because of the fact that you get thrown back to the beginning of the level, the time between you making a mistake and trying that same place is too long. By the time you get back to the part where you died, you've forgotten what you did wrong, so you can't try a slightly different approach. Because of this, I have still haven't beaten the level.