It's a very hard story to understand, and even harder if you havent got the alternate ending from collecting the hidden stars.
#MASSIVE BIG SPOILER GTFO STYLEE#
#MASSIVE BIG SPOILER GTFO STYLEE#
#MASSIVE BIG SPOILER GTFO STYLEE#
#MASSIVE BIG SPOILER GTFO STYLEE#
#MASSIVE BIG SPOILER GTFO STYLEE#
It's the story of the creation of the atomic bomb.
The princess is the bomb, and Tim is it's creator. The game and gameplay relate little to the story apart from it's thoughts. (What if it were possible to rewind time? What if it were possible to be in two places at once, all come up in the story).
Have a read of this
plot analysis if you really want to know what it's about.