This game was the first M rated game published by EA. According to American McGee, he fought for the rating because he didn't want parents to buy the game thinking it was for children.

In retrospect, McGee stated he regretted fighting for such a high rating, believing the game wasn't violent enough to warrant it.
Contributed by Takahashi2212
In the console versions of the 2011 rerelease, the main menu and loading screens are rendered in 4:3, as opposed to 16:9 like the rest of the game. As such, they feature a border. This border is not featured in the PC version of the rerelease, since the main menu and loading screens are rendered in 16:9 like the rest of the game. However, the border is still in the PC version's files as "border1_left.tga".

Similarly, the console versions also feature a title screen, which goes unused in the PC version since neither the 2000 original or the 2011 version have a title screen. This is also in the PC versions files, as "title_bg.tga".
Contributed by Takahashi2212
In one of the cutscenes in the game, Alice will say the line "I shouldn't think so. I'm a person, and just now I wish to become very small. About this big." However, there is a different take of the line in the game's files that goes "I shouldn't think so. I'm a girl, and just now I wish to become very small. About this big.", replacing the word 'person' with 'girl.'

Both the original release and the 2011 rerelease use the version with "person" in it, so this different take goes unused.
Contributed by Takahashi2212
The symbols on Alice's dress have changed throughout promotional artwork and the several releases of the game.

In original promotional artwork, the symbols are the symbol of Neptune and the symbol of Jupiter. In game, the symbols are the symbol of Venus rotated 45 degrees to the left, and a sextile.

In the 2011 rerelease of the game, the symbols are the symbol of Eris, and the symbol of Jupiter. This makes the design fall in line with its appearance in the sequel, Alice: Madness Returns.

When American McGee was asked about the symbols he said "the difference in symbols might have to do with poor communication/planning and/or might have to do with the marketing department being overly sensitive about the symbols and their meanings. Too much time has passed for me to remember exactly what caused the differences."
Contributed by Takahashi2212
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In the White Castle located in the Pale Realm, there is a portrait of Lewis Carroll, the author of the original Alice in Wonderland novels.
Contributed by Boyobmas
In a prerelease trailer for the game, the background music is a reprise of several songs spliced together from Sleepy Hollow and Edward Scissorhands, both composed by Danny Elfman.
Contributed by Electra
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The cover of the game, showing Alice holding the Vorpal Blade with blood splattered on her dress, was deemed too violent for store shelves in some regions. Alternate versions of the cover include her holding the Playing Cards or Ice Wand instead, with the blood removed.
Contributed by Electra
During development, Marylin Manson was involved in producing music for the soundtrack. He left the production team early on, but his contributions still made it into the final game, mostly in the influence of alchemy and The Mad Hatter.
Contributed by Outofmind23
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In early screenshots and beta art work, Alice had two different necklaces. The first was an A pendant and the other was an upside-down cross. Neither made it to the final version, in which Alice wears her omega necklace.
Contributed by gamemaster1991