So I watched all 3 seasons and greatly enjoyed them. It definitely was a roller-coaster ride of emotions and subject matter. As a young adult I feel that there are definitely some life lessons in here for all ages. Granted kids may not understand some themes, if they're not in that situation. Still they may recognize some tid bits, that maybe a friend is going through. For young kids(6 and up) I would greatly recommend an adult present for viewing of season 2 and 3 followed by a Q&A (strictly my opinion).
A show with a short run time each ep, gave me comedy, suspense, mystery, tragedy, adventure and more.
All in All I'm hoping a 4th season will be greenlit and the production team gets back together. If not, some comics or graphic novel would be appreciated.