The sprite file at the link on the Resources page for this lesson:
is screwed up. It came up as the lesson, with a giant spikes image that is super low resolution (2500 x 2500), way down at the bottom of the page - I almost missed it.
I just grabbed the image and shrunk it in GIMP, but you might want to fix the link and file, so it matches the rest of the course in quality.
Thank you,
Jim
P.S. I suggest you delete message after this is fixed, as this message will irrelevant then. J.