I recently completed graphics for an app game using blender. It was designed by gamers to be a fun app game with the intent of making learning fun and exciting (well, as fun as an app game can be) to help you learn. It’s actually pretty nice.
The backgrounds all fit seamlessly together - the camera is keyed to turn as many degrees as the FOV per frame.
I worked with toon textures in blender internal to create a happy bright sunny smooth feel.
I used cycles to create the icon, and make the ingame tiles 3D (I had to work with 180x120 px tilesheets).