1. Open the link below and download a language of your choice:
https://drive.google.com/drive/folders/1UpBM4TiRf1uk74C1H-4QVteWwMpKMAjP?usp=sharing

2. Put the "LocalizeData" folder into the "Extra Language" folder inside SuperMarioGravity_NewDemo

3. Enable "Extra Language" in the Riivolution settings (see ReadMe.txt) before starting the game