I don't get why there is a choice for player input, when there are almost always predefined answers, and not giving them crashes the game. Text adventures solve this problem by giving one generic output for inputs that are completely unrecognized and maybe some more specific answers, if it recognizes certain keywords. If there is no flexibility, use predefined buttons like a visual novel, if you want the player to try different interactions, have some predefined and some generic answers, to facility experimentation.