I remember seeing the WIP of this months ago during the NG Summer Festival.
As an amateur in Flipnote (and by extension other media creation tools) I'm always impressed seeing what's possible with them when they're put into capable hands. I can't imagine how tedious it must've been to draw all the sprites and mouth shapes, meticulously shade each one with unique frames, and then animate them like little paper dolls without the luxury of folders to keep track of everything. Recreating that SNES blur effect to mimic a camera shifting focus between two things on screen was also a nice touch.