Wait, DEC 10th!? yes! sorry Minecraft..
That one I can answer!
3DS video capture (at least the one they used) doesn't also grab the in-game sound. So it had to be cobbled together in the trailer. We had them fix a handful of them, but some made it past. Sorry about that - the in game sounds should be just fine though.
Well i was wanting to know as I have the PC version and was hoping for some of the unique mobile (and or) console bosses. I would also be happy if the wii U/3ds versions had special bosses all their own.