Lock screen is Satorl Marsh by Orioto on Artstation Home screen and All Games screen is Clean XCDE menu screen wallpapers by u/Aqryllic on Reddit, upscaled by u/Chaos-Kiwi Player select menu is the above but darkened with a custom curve in paint.net Settings menu and user page are the Xenoblade Chronicles Eryth Sea concept art with some blurs and curves to make the text behind it readable.