Right before the end of the game, there was a small error that prevented you from getting back to Earth (the orb will float over your head instead standing right in front of you---thus gamebreakage). That has been fixed, so if anyone downloaded the game before 3/1/2010, I recommend downloading it again.
Don't worry, you can still use the same save files!
I apologize for the inconvenience! The game page's download link has been updated.