Nice work porting the game to various OSes and enabling translation!
I made a translation to Esperanto, based on my translation mod for Spelunky HD.
Here's a download with my locale files for Classic HD: [link]
the line for locales.json is
"eo": "ESPERANTO"
I also found a bug related to localization. In my game (Windows debug version) the "DONATE:" string shows up in English, regardless of what I enter in the text,json.
There are also several strings that are apparently indented instead of centered, most notably "GAME OVER" and "FINISHED!", which makes my translated strings off-center when they have a different amount of characters. But this is only a minor issue.