Arthur's theory of aging
'Baby' and 'Toddler' are the tutorial stages of humanity. Then you advance to 'Kid,' and go through several levels there, until you reach 'Advanced Kid' at age 10. Once you complete 'Advanced Kid', you progress into 'Teenager', and work your way through several levels there as well, before reaching 'Adult' at the age of 19. Beyond that, the ages get a little hazy. I am apparently Level 54, and a 'Medium-level Adult,' while Steve is an 'Advanced Adult'. I'm sure Arthur's grandparents will be delighted to know they are are 'Expert Adults.' Arthur also reports that "If you die at the 'advanced' stage, you don't get to make it to 'expert'."
I don't know what the boss battle at the end is (but then, I suspect no one does.)
I don't know what the boss battle at the end is (but then, I suspect no one does.)