You're contradicting yourself here. First you're saying that the controls must keep their size in pixels, then you say you want the GUI to be proportionate. The two are on the opposite ends of the spectrum. 200 pixels on 1920x1080 is way different from 200 pixels on 320x480, so which one do you want? If you want them to be the same size proportionally, set your UIRoot to be manual and define the target size you want. If you want them to be pixel-perfect (same size in pixels, thus being bigger / smaller on different resolutions), then leave UIRoot as automatic. In either case, you will want to use UIAnchor to position widgets in corners and attached to sides of the screen.