When Catherine was localized for North America, there were changes from the original content. Things like changes to the Difficulties were well-publicized, but here is a list of more obscure changes that happened.
- The North American Art Book is almost twice the width of the Japanese Art Book, and double the length: 32 pages instead of 13. This is due to the French translation.
- The illustrations in the North American Art Book are full color rather than stylized red and black.
- There is a lot more information in the North American Art Book.
- While the North American's sound disc came packaged in the Art Book, the Japanese version had its own slim-CD case to hold the book and cd.
- The North American version is patched by default, and is impossible to remove. In the Japanese version you could switch between "Original" and "Alternate" by pushing L3+R3 together.
- Undo was not available in the Normal difficulty on the Japanese version, as it is in the North American version.
- A different sound byte for the English "New Mail" arrival is used in the North American version.
- Trophies are linked, so it's impossible to double Platinum. It's not yet known if Xbox 360 Achievements are linked as well. However, the EU version has a seperate trophy list, so you can double platinum between the NA/JP and EU version.
- No save files can be transferred between versions.