They are great, if you are not playing them then you are missing out on the best emotionally/decision driven game this year.
There are 5 episodes to complete the whole game, episode 1 and 2 have been released, the next episode is supposed to be out monthly, so next month, but they were late for episode 2 by like a month and a half, so within the next 1-3 months the next episode comes out. You can buy the "season pass" for $20 and get all the episodes as they unlock monthly (that will unlock episode 1 and 2 now for you to play), or you can buy the episodes individually for $5 each. Each episode is about 3 hours long and very much worth it.
“Anna, my strong, terrifying Anna.” -Cas
"You lack the requisite spine and testicular fortitude to study under me" -Elodin