I want to say that the game Harmony Haven is also a similar content to yours, 20 minutes long, but this game at least has animation, but you don't have it. So I'm looking again at the beginning 8 and the end 29, and again we see pictures with text. Your game is hard to call a novella. This novella should be a visual novel or a visual novel - a genre of computer games, a subtype of text quest, in which the story is shown using text, static or animated images, as well as sound and/or music. But you don't have either one.