at resolution switching, the assets are not changed. This would incur a huge runtime performance hit. Thus the assets used are the ones that match your screen resolution, on Desktop that is mostly hd2. To still simulate other assets, you can call
in your main.cpp and set it either to 1 (for sd images), 2 for hd or 4 for hd2 images.
See the Flappy Bird demo where this is used.