This is a strength for a program that stresses language learning without the use of native languages. Communicative CALL will be flexible. Basically, the program is not flexible as only one answer will satisfy it. Communicative CALL will allow the student to explore the subject matter. Here again, there is a partial success.
Students can even skip around within the lesson.
These are only superficial forms of flexibility. Students are very limited on what they can explore. Communicative CALL will create an environment in which using the target language feels natural, both on screen and off. To me, this never appeared. There was no natural feel to any of the material.