It really will make you better
Let's get this out of the way: I am not good at basketball. But after playing NBA Baller Beats for just a few hours, I could consistently dribble with my off-hand for the first time ever.
Like any rhythm-based game, you'll have to be able to keep a beat. But dribbling a real basketball in time with the music isn't like playing on a plastic guitar. It's the real deal.
The game doesn't ask what your dominant hand is, and you're going to be challenged no matter what difficulty you choose to play on. Even on "rookie," you'll be confronted with rather intricate beats and through-the-legs moves. It's an incredible workout, and surprisingly fun.