Hi everybody,
I would like to share my experience with whom of you is waiting for the phone call. I think that, as Mustang888 said, they basically want to check your english. With me they started with questions about ATPL, licenses, medical, MCC and so on to check whether everything was in order. Then we kinda went through some HR questions (why you, why Ryanair,...). I think that this second part comes up depending on how good your english sounds to them in the first part of the phone call (evidently my english wasn't bad since I was invited for the assessment, but still not good enough to spare me from a deeper check
).