In the exploration I linked, the only types of interaction offered to the learner were either ok/proceed, or 'answer this textual multiple choice question'. This may make it seem like Oppia doesn't do much more than software for interactive fiction.
There are more similarity between things like Oppia and interactive fiction, I don't see them at odds. It is is wonderful that Oppia has a musical notation interface.
If you zoom out far enough, everything could be considered a quiz.
BUT Oppia has lots of other interaction types: https://github.com/oppia/oppia/tree/develop/extensions/inter...
For example, you can input music notes: https://github.com/oppia/oppia/issues/4842
Or ask the learner to enter a fraction, or to sort some objects.