Originally, if Mickey used too much thinner when he was in his 'scrapper' mood, he would've turned into a design called 'Thinner Mickey'. Every evil action that Mickey would have done erased his paint and showed more of his basic line-art. The idea was eventually scrapped due to the Disney company not wishing to tarnish Mickey's 'heroic' attitude.

During development, the bunny children came in four different colors: black, white, light red, and light blue. The final game features only light blue bunnies.

According to Warren Spector, there were originally three different designs for Mickey, with his appearance changing based on whether the player made heroic or mischievous choices. The designs were based off different eras of Mickey Mouse cartoons. Hero Mickey was based on his old movie posters, Wasterlander was based on 1930s vintage Mickey, and Scrapper was inspired by the early black and white Mickey cartoons (along with the 1995 Mickey Mouse short 'Runaway Brain').

Mickey is aided throughout the game by Gus and other creatures based off of "The Gremlins", an unproduced film collaboration between Disney and author Roald Dahl that dates back to World War II.

It was originally intended for Wonderland to appear in the game. The world can still be seen in the opening and closing cinematics.

When first meeting Gremlin Calvin in Dark Beauty Castle, he is wearing a yellow suit. When saved, he reappears in Gremlin Village, now sporting a green suit.

Spatters were originally going to be a variety of colors, as was the splat of paint on their heads.

The official Epic Mickey strategy guide misidentifies Gremlin Trigo as Gremlin Tringo.

In the E3 trailer of Epic Mickey, the Mad Doctor is seen in the black cape uniform like in the cartoon 'The Mad Doctor'. This was changed in the final game to avoid confusing him with the shadow blot.

There is a hidden room on Mickeyjunk Mountain containing a basketball backboard. It is a tribute to a secret half court in the peak of the Matterhorn Bobsleds ride at Disneyland which employees built for use between shifts.

In Mickey Junk Mountain, a can with Donald Duck holding a glass of juice is seen among the piles of junk in the game. This is a reference to a brand of orange juice from the Florida's Natural Growers agricultural cooperative that used Donald Duck to market its orange juice, even using Donald as its mascot.

The Mickey Junk Mountain area is based off of the Matterhorn attraction from Disneyland. But Instead of snow, its made out of actual Mickey Mouse merchandise produced throughout the years.

The music that plays when Yen Sid is seen painting the Wasteland is Paul Duka's musical adaption of the poem "The Sorcerer's Apprentice" popularized by Fantasia, the 1940 Disney animated movie where Yen Sid made his first appearance.

During development of Epic Mickey, Warren Spector used clips from various Mickey Mouse cartoons from the golden age as reference for Mickey's character animation. By recreating some scenes from some of the cartoons and overlaying it with the cartoon, the team were informed of how Mickey should move throughout the game.

Within the game files are unfinished videos for two unused sketches: the balloon and the fireworks. It’s likely the fireworks sketch became the fireworks mechanic in Epic Mickey 2: The Power of Two.

According to Warren Spector. He considers Epic Mickey (and Deus Ex) as the high point of his career for bringing back the character Oswald the Lucky Rabbit and getting fan mail regarding his work on Epic Mickey from fans:


It should be noted that Ortensia was not technically an original creation for Epic Mickey, as she already existed in the Oswald cartoons under the name Sadie. However, Ortensia would become the character's official name in the Disney Parks and merchandise following the game's release.

In 2021, a 15-second clip of beta animations for the game dating back to 2006-2007 was discovered on the website of animator Michael Daubert, a former employee of the outsourcing studio The Animation Farm who produced animations for an internal pitch of an early iteration of the game. These tests showcase a completely different art style from the final game and unused gameplay elements, with Mickey shooting ink out of his body to quickly surf around, and jumping and slamming the ground to summon a tidal wave of ink to attack large Blotling enemies. This tidal wave attack also causes Mickey to lose all of his colors, turn white and become exhausted, suggesting that the known early idea of ink/paint/thinner usage changing his physical appearance was going to involve a stamina meter tied to his attacks. Mickey's early design was more stylized compared to his traditional appearance in the final game, featuring a prominently tall forehead, a lanky, stretched body, no visible mouth, and crooked oval ears. This early design would live on through an emblem used in promotional materials and as a recurring icon throughout the final game, with the inky black outline of the early design's head forming an "M".

In 2024, an extended pitch trailer for this version of the game using some of the same animation footage was posted online by Thomas Heimann, another former employee of The Animation Farm. The pitch for this version of the game proposed a 2008 release date and outlined possible gameplay mechanics, an early version of the story, and early character designs for Mickey, the Phantom Blot, and the Blotlings. A model sheet for Oswald the Lucky Rabbit with character designs dating back to his initial usage in the 1920s-30s was also teased during the trailer, but he does not appear in it.

Pluto's bowl and bone can be seen in Mickey's house.

At the end of the game, once Mickey gets back to his world, his calendar reads the date as "November 18th". This date is the release date of Steamboat Willie, the very first Mickey cartoon, November 18th 1928. November 18th was also the release date for Epic Mickey 2: The Power of Two in North America.

On Mickey Junk Mountain (Wasteland version of the Matterhorn) you can see a number of old NES and SNES Mickey Mouse game cartridges made by Capcom.