I've got mixed opinions of this. Super Mario Run was ok...but that was also a paid game. The moment I see free to play, I feel like it is going to be limited by the same stupid timers all the free games have, which just make me proceed to uninstall them 3 days later.
I actually like the timers. They help to minimize my little addictions when they develop. I'm more concerned about whether the game will be any fun or if it will be a blight on the Mario Kart name.