Godot also offers the viewport stretch option for low-res output at any actual resolution, so if you'd like you can also display low-poly graphics in what looks like 480p (imitating the original 480i).
@TwistedTwigleg -- That second clip is a nifty shader! I had not thought of Godot imitating the PS1's jittering vertices (from integer pixel positions) and missing perspective projection on textures.
Following through the links it's apparently this shader here, though the GitHub page does not detail either of those effects.
