Move the Game_EN.exe file into the game folder as shown in the screenshot above.
If you'd like to play the game in Japanese, please use the original Game.exe file.
Both versions utilize the same save file, so you'll be able to continue playing with no issues.
The .exe file is safe but your system may flag it as a virus.
If you are having trouble opening the file, please adjust the settings of your security software and give the files permission to run.