Huh. Well this seems fitting.
It's exactly what it sounds like: Halo 5's dusty, burlap-sack-clad trailer done up in Minecraft style by way of animation program Maya. It's basically shot-for-shot, near as I can tell. Damn impressive, in other words.
For reference, here's the original Halo 5 trailer:
This project was actually created before Microsoft's purchase of Minecraft studio Mojang happened, so it's kind of weirdly prescient in that sense. Then again this is hardly the first time everybody's favorite green cybernetic giant has roamed Minecraft's equally green vistas.
If you want to know more about when you'll actually be able to play Halo 5 (kinda), I wrote this thing.
Thanks for the tip, David V!