Oh, thanks! ^^ I don't know about a tutorial, but I used a viewport and a subviewport container, and made that resolution of the viewport half the resolution of the game, so that it looked more pixelated. And there are a bunch of retro shaders you can find for godot online, I forget which ones I settled on. And everything else was just... making all the models low poly, and the textures low resolution, and setting all the sampling of materials to nearest instead of linear.