The first original enemy discovered on Enceladus is a lowly inchworm.
This isn’t the enemy that I set out to make today, but it is the one that I was attracted to as I started drawing. Something about the worm motion was very appealing, and I realized I could just distort a single image to animate it pretty convincingly. So this is what I got. He’s a little tougher than he looks, mostly because when flattened he can duck underneath a crouching shot.
Implementation note: the code that implements the logic to turn the worm around when he reaches the edge of a platform is labeled, in a comment, as the “Roomba cliff sensor.”