hmm everything scales in proportion up/down based on players screen resolution in fullscreen mode.
for example if you create a game with default resolution of 1920x1080 then all your scene backgrounds have to be at least 1920x1080 or greater & your menu scenes should be 1920x1080.
If you were to set a custom resolution while in fullscreen mode it wouldn't scale the game up/down to the players resolution - I'm not sure why... you just get more black space, which is why after you've exported your game you should set resolution to auto or desktop.
I'm not at the development stage of my game yet. planning & concept artwork is currently in progress - by work, I meant in general - for example the various Lua Script & template project files I share on here.
-- taken from messages.txt log file.
Initializing graphics interface. Surface size: 640x480, render size: 1024x768
Initializing graphics interface. Surface size: 1280x800, render size: 1024x768
P.S: the attachments are from the demo game that come with VS or rather it's a screenshot of a technical demo I've made for dynamic sound control using the latest developer build (I'm not allowed to share it yet) - I often use VS demo files when testing scripts or for the templates I share - easier