It makes the really good point that WarioWare is basically game design stripped back to its simplest form, and the success of the series comes from how it teaches players how to take on challenges with nothing more than a single word and button press/command.
Additionally, the video also goes over some examples of good and bad design in the microgames themselves, comparing the easy to grasp and logical set up of Crazy Cars with the more awkward and perhaps less well thought out set up of Nighttime Allergies.
So yeah, it's definitely a video that WarioWare fans (and game designers in training) should watch!