The Game Gear and Master System version of Daffy Duck in Hollywood has a set of 3 cheat codes - the first 2 being a stage select code and an invincibility code. If you enter those in that order and then the third code, Daffy's sprite will be replaced with a digitized image of Probe founder Fergus McGovern.

A prototype version of the game was distributed on some pirated cartridges featuring stickers for the game Daffy Duck: The Marvin Missions. The level select screen uses an unused rendition of "Hooray for Hollywood", while the Game Over screen uses the "That's All Folks!" theme. This is unlike the final version, which instead reuses the introduction and main menu music respectively. Other differences include the language selection screen being absent, and lives counting from 0 instead of 1.

The Genesis version of the game was originally planned to use a rendition of Richard A. Whiting's "Hooray for Hollywood" arranged by the game's composer Matt Furniss instead of the story theme found in the final game. The song was most likely cut due to licensing issues.