1- Either the team has already setup a language anbstraction layer, either they didn't.
If they didn't, dev the abstraction layer -> 1 week dev
- Abstraction objects
- User serttings UI
- Clean the code and replace by constant + object calls
- Content of the drop down is dynamic and source the flat files list + content.
Content files -> 1 day dev
- Initialize the translation with google translate or chat gpt
File maintenance - Option 1
Leverage on feeback and reports to update the files and refresh the content regularly.
File maintenance - Option 2
Put the files on GIT and get the community to help update the content.
**Yes there will be issues with **
- sentences too long or too short
- non-latin languages display issues
- translation mistakes
- etc
But you opened your game to all people on the planet for minimal dev time. Pretty sure the community content generated from the game in different language will be worth it.
Then you just refresh the langugage files as regularly as possible to correct mistake people report OR just refresh the files if the community can update it via GIT.