series comes on tomorrow with a two-part premiere. There are several shorts that set the stage on the site. Disney actually ran them and I watched them last night.
It seems like they've got a wide variety of characters and villains. I've always been more of a DC fanboy than Marvel, but the shorts were enjoyable. Since it's Disney, it's rated Y7. In the shorts, there was a few implied deaths, but nothing graphic shown. If someone is shown down, they go out of their way to demonstrate that they are still alive.
Bonus: Nolan North as Baldur