Hey, thank you for the kind words! All of the art was drawn with Autodesk Sketchbook, exported as transparent PNGs for importing into Construct. Most of the art was drawn at the size that it displays on-screen (the game runs at 720p because honestly, this type of art really doesn't need 1080p) except for some of the really big background assets (mountains and planets and the like), which were drawn at 50% scale and enlarged in the C2 layout editor (this can work well for assets that are supposed to look a little fuzzy!)
I was considering maybe making some behind-the-scenes videos at some point - don't know if that might interest you? :)