I (tried) to create a playground scene in blender.
Please note that I’m still learning cycles (although this isn’t from a tutorial)
I think the frame is a bit thick, but it could be your design.
There is a nice contrast between the plasticness of the frame and the metallicity of the swings/seats.
The grass is a tad high, do you want it so?
The chains holding the seats are a tad lax, they could be tighter. That could be done with some rigid body physics (if you don’t want to do it by hand).
Nice model. Keep at it!