Something you can potentially do is set your game.project file to half the resolution you plan, and then in your GUI nodes and so on set the base scale to 0.5 to half them too (make sure it’s uniform across x,y,z and not only x,y). This is what we do in our games. You’ll likely need to disable mipmaps / use something like this instead of the standard materials Sharp Sprite - RGSS for Defold
Not sure if it’s an issue with the game.project setting or elsewhere.