Sorry not quite sure I follow, source file? You can find every frame on the .png download. With that you can just resize/copy parts to make bigger scenes and change the colours.
It's all designed for the gameboy so it's based on a 160x144 pixel resolution. Enlarging pixel art as a whole doesn't really work, you can really only scale it by wholes, like x2, x4, x8, x16. Depending on your art program you should have the ability to do that.
