It might be an interesting academic question, though I am not much into such things. With respect to what should be accepted for ParserComp, I don't think it should be based on some definition of e.g. "dynamically derivative" but rather expectations boiled down to something easily understandable, though there would always be grey areas. My opinion (might need tweaking): "Games accepted for ParserComp should be games where you type commands to someone or something throughout the game." This should cover any genre (sci-fi, Fantasy, rpg etc) and original mechanics (the character might misbehave, don't understand, or commands must be in a fictive language etc etc). So the player must try to command someone/something through typing most of the time. For instance, games which do not fulfil that could be moved to a sister-competition with links at the top of the ParserComp page, similar to the Back Garden of Spring Thing.