Advance Wars

Advance Wars is a light-hearted turn-based strategy game for Game Boy Advance. It's actually part of a much larger series that has existed since the days of the NES/Famicom, but this is the first entry to see an international release, much like the Fire Emblem series.

Hidden "Nintendo" Design Map
While not technically cut, this is a relatively obscure feature. Holding the L and R buttons while opening the "Design Maps" function will automatically load a map which spells Nintendo in Japanese. It is identical to the version in Advance Wars 2.

Combination Cartridge
The Japanese version of Advance Wars and Advance Wars 2 were distributed together as "Gameboy Wars Advance 1 & 2" in a single cartridge. The game has a unique game selector screen not seen in the US or EU versions.

COs
During the localization process, minor to significant changes were made to many of the CO's sprites from the Japanese to the US release of the game. Many of the changes appear to make the characters' appearances more formal in terms of military dress as well as to remove references.

Nell
Nell's buttoned tank top and short skirt was converted to a full shirt and a skirt that reaches the knees.

Olaf
Olaf's hair and beard were changed from white to brown as well, and the traditional 'Santa Claus' hat was replaced with one reminiscent of stereotypical Russian Officers.

Kanbei
Kanbei's change is probably the most striking - he was changed from what looks like a traditional Samurai to more of a World War 2 era Japanese general, losing the ponytail and samurai armor. The sword is kept, though.

Drake
Drake was changed from what looks like a traditional pirate to a more modern naval captain; sporting a captain's hat instead of a do-rag, as well as a proper naval uniform instead of a jacket.

Grit
Grit's only uniform change was from a blue-trimmed cowboy hat to what appears to be a Russian-styled military cap.

Sonja
Sonja's glasses were removed - changing her look from a stereotypical booksmart Japanese schoolgirl to an image slightly more suited for an intelligence and recon officer. Her uniform was also changed from red to green.