No pranking, no real adult themes. Lots of silly games that while I might not enjoy are at least not crossing any clear morality lines. It might not be Mr. Wizard but pretty wholesome compared to the other stuff I have seen online.
Additionally from the interviews I have seen from him, he seems grounded and treats his employees well.
There are different ways to define "wholesome" but when looking at clips/videos of that get mass produced these days, I could see classifying his as wholesome.