This is a full hour of multiplayer from Halo 5: Guardians, taken at HaloFest last month in Los Angeles. It's a good look at what should be in store when Halo 5's beta gets going at the end of this month.
The video, by YouTube's Ready Up Live, showcases two maps (Empire and Crossfire) as well as the full range of abilities offered in Halo 5. That includes Stabilizer, Ground Pound, Clamber, Thruster Pack, Spartan Charge and Slide, which you may read more about here.
Halo 5: Guardians' beta will last three weeks once it starts Dec. 29. So far, the only known way to get into it is to buy Halo: The Master Chief Collection. 343 Industries says it'll be "real" beta to test and tune the game, scheduled for release sometime in 2015.