The only member of the voice cast of "Harvey Birdman: Attorney at Law" to not reprise their role in the game is Stephen Colbert, who voiced Phil Ken Sebben and Myron Reducto. These roles are respectively replaced by Stephen Stanton and Crispin Freeman.

There are several characters and references to Capcom's Street Fighter series through the game, such as:
• Harvey Birdman accidentally lights Guile's hair on fire.
• A magazine can be seen with the name "P. Cock" on the front, possibly referencing T. Hawk.
• Dhalsim appears when Harvey proclaims that his desk is missing because the office is "going zen".
• Zangief appears after Harvey proclaims that Dum Dum is offering an evil scheme.
• Ryu's portrait appears on Peanut's fake ID, with the name Nobuyuki Johnson.
• Chun Li appears as a guest at Harvey's retirement party.
• Street Fighter III appears as a SNES cartridge, as an icon on Harvey's computer desktop, and as an Arcade machine.