So it really only have one mission. I got another question, how long a regular session is?
I’d say anything between 1 to 2 hours, depending on how much players are invested in the mission? Since it’s up to them to determine when it ends, it can vary greatly.
I've just watched someone playing it solo on YouTube and he used three or four prompts and got almost an hour of gameplay. So a single matrix probably has enough material for a short campaign!