So, my game is soon ready to launch - but I´m worried its too big when it comes to gigabytes. What determines the size? All the assets in the project, or only the assets used in the game? I have maybe 100+ items in my assets library, but only use 40+ in my actual game. When I export the game, will it only take the 40 assets or will it also take the unused materials as well? And if I have an assets that is 100% size in the library, but I scale it down to 50% in the game - will it still be counted as a 100% big asset? i.e. if the asset original size is 1 mb, but I scale it down 50%, will it be 500kb in the exported game, or still 1 mb?
It will load up everything in the library. So you should remove everything that is not being used inside the game.