Originally Posted by ToroMor

Very well.
- they are all called "final fantasy"
- recurring enemies/monsters
- rather similar battle systems
- recurring items
- recurring jobs/classes (red mage etc)
- funny ship/airship animations j/k
- similar menu & message box design (not in FFX though)
- recurring spells
- recurring weapons
- recurring names taken from different sources (mythology, fantasy, history, movies..)

and whatnot... *drunken mumbling*