Personally, i have never played any of the warioware games. Thankfully there is a demo to play and it actually made me want to buy the full game. The story mode is at least 2 hours long but im not saying its a bad thing. I think its fitting for a game that just here to hop in and hop out. I like each characters mechanic and controls. it feels like they're also bringing their personality into the game, which i really like. Of course, the game is about bringing your friends and playing together. It is a fun party game to bring and a decent game to play solo. Although, it is not a game that will make you grind for 300 hours. Like I said, it is a casual game to past the time.
It is good to listen to other reviews from time to time but for this game, I say it is all up to you. Dont listen to the reviews of this game. I swear, I don't know what they're smoking.