Selecting a word that Sayori likes will cause her icon to bounce up and down.
If you’re playing the Steam version, right-click Doki Doki Literature Club in the my games section of your Steam library, then click properties, local files, browse local files…, characters. If you’ve downloaded the game from the website, simply find the file in the characters folder that is located in the same folder that you use to launch the game. You must delete the ‘monika.chr’ file in the game’s files directory.
Doki Doki Literature Club is not a traditional visual novel.