The DS Start menu icons for the first four games in the series feature Layton gradually smiling more with each game before ending by pointing at something.
Contributed by MehDeletingLater
The character Phoenix Wright (from the Ace Attorney series) influenced the creation of Professor Layton's protagonist and namesake. Level-5, the developer of the Professor Layton series, "researched the good and bad points of Phoenix Wright [and] developed the good points".
