Played it for about 3 hours and got sick of it. Depending on what you want to accomplish, and if you consider seeing the credits as being beaten, I can say I beat it in about 15 min.
This seems to be designed with a heavy emphasis on multi-player, as the single-player mode doesn't offer much to do. By the 3rd time going through the Classic and Adventure modes, I was already bored with doing the same small number of stages over and over. The Stadium events did nothing for me. The Home Run Contest is poorly designed, as there is no retry option, So, after every attempt, you're kicked back to the character selection screen. Considering the event is 10 seconds long, until you start to master it, you'll spend almost as much time waiting for the event and character selection screen to load as you spend actually doing anything.
Update after reviewing it:
There is a retry option in the HR Contest, I just didn't notice it. It's in the Pause menu. So, if you don't pause it, you won't see it. Also, if you retry, your result is nullified. So, if you set a new record and then retry, you lose that new record. So, my position still stands that it's poorly designed.
