In fact, it's basically as if there were a full WarioWare game included in the package. The sample minigames, like those in other Wares, are divided into groups based on which WarioWare employee "created" them. Mona's games are "Strange," like in the original GBA game. Jimmy T's theme is "Sports," Ashley's is "Food," Orbulon's games are "IQ" themed, and 9-Volt is "Nintendo."
Not only can you play these sample minigames, you can open them up and mess with them! You can alter the art and music (and look at, but not alter the base gameplay) in the samples, as well as games that you get from your friends.