Is there a way to reset the game to its original state; i.e. wipe clean all saved achievements? I have been unable to get the final achievement. Yes, i have used a hint but the the hidden portal on the second world (red) appears to be missing. I believe it is in the transition area before entering into the area where one initially releases the ball.
There appears to be some leftover saves from previous attempts. that have been removed. I think that by start over fresh without any history might help.
PS this is a great game.