I may be wrong but I think your interpretation is pretty close to the story page at the start of Braid.
For goodness sake, Mario IS the castle, repeatedly making the journey inside his own soul to see if he can finally find that part of him that is capable of love, but again and again finding out there's nothing but hurt. Not only that, but every time he feels a part of himself slipping away, he has to sit and watch his brother do exactly the same thing.
And also he hates turtle. Seriously, screw them.