Art progression of Type Knight over its development.

(right click + open image in new tab to view it in full)

FYI: The art of the game comes from a lot of different sources. It's a mix of creative commons assets (all modified, some more than others) and original work. 

Personally I'm only responsible for the palette swap in july, the later version of the clouds, the later version of the skeletons (very similar to the original but with proportions closer to the knight), the special effects like the fog and the rain.