how is the best way to work with those problems? how i create one game to work in many size and resolutions from screen?
tks
I would focus on aspect ratio (unless you are creating pixel accurate 2D game). Make sure that the gameplay and the GUI works with aspect ratios between 4:3 and 2:1. Unity does OKish scaling with bitmap fonts, but if you want e.g. crisp text with every device, you have to use dynamic font with DPI aware font sizes.