Pretty much it's 8 episodes of Halo cartoon animated by different people. I haven't watched all eight but, they're pretty bad.
Spoilers.
First two are about the forerunners and stuff and how they saved the universe and stuff.
Third one I didn't watch because it was some water color, slow animated, stuff about elites.
Fourth one was the typical badass anime hoe who always has the same stupid expression, she led some guys into battle and then got shot and had this bear keychain.
Fifth one was pretty much Dragonball Z with a spartan, the spartan's name was 1337 and he got aten by a dino.
Sixth one I fell asleep on.