Our latest project is remaking the UI of GMAGE, so far this is what we do...
Brave Color
Why Brave ? Cause it'll be good combination between white and they can keep focus in the app.
Flat Design
The target of this game is children, So we want they're comfort even in the home page, and choosing flat design is the best step cause it's have more clearly and soft composition art.
Leveling Button
it's like an 3D things in 2D, manipulation it for kids imagination.