When playing with my brother using local splitscreen (horizontal if that helps) the animations for the other player just stop. Like walking is just the arms to the side, legs no moving as the character slides around. Items don't appear in hands and the blocks being broken also don't show the breaking animation, you just hear the sound until its gone.

It randomly occurs (as far as I can tell) and effects both players. I'm currently trying to get a refund of the game.

side note: I called Nintendo Australia support about getting a refund and they said the bug where it signs you out everytime the game closes was a freakin security feature. What the hell?!