For me at least its perhaps confusion with the fact that we are talking about sliders , in under the "App and Site Blocking" menu.. so is a slider in the 'on' position doing an App Block or App Allow? maybe the menu option should have been "Allowed App and Sites" or "App and Sites overrides" ..
Yes, therefore, Steam was enabled for "Kids" as was Minecraft Online , (also re the sliders, why can I have both those sliders 'on' yet the 'Gaming' slider in off? (and visa-versa) .. I do have all 3 on the 'on/right' setting, but again its a little counterintuitive as to what it would mean if gaming is on yet both the sub choices are off.. or other way around.. gaming off yet one or both sub-choices are on..)
The only other Category I have enabled for 'kids' @ present is "Search Engines" and the "Google SafeSearch" listed within.