1st: extract the file you downloaded.
2nd: inside THAT file, you'll find another 3 files. Ignore the screenshots folder and the 'Miembros del equipo, escuela y contacto' text. You have to extract the other 'Sweet Dreams (In)Sanitarium.rar' file.
3rd: inside this last file, you'll find the Sweet Dreams (In)Sanitarium application. You have to run that.