Quoted from Frax:Fantastic if it's 2 young kids, maybe. Playing with your own kid? Frustrating as hell, and my 7 year old is a pretty competent Overwatch player. The camera is dumber than a sack of bricks. The game isn't designed for that. They need options to change the camera distance from Mario, or to have it be static facing the direction Mario is, in order for 2p co-op to be viable, IMO. Having to stop, hold down a button, then use the stick to rotate the camera sucks. :\
I use a set of joy-cons and my son plays as Cappy with one single joy con. Eliminates most problems except when he throws crappy and forgets to reel him back in.