New languages are intriguing, and seems to me Lily definitely has potential, though of course I need to learn more about it. My immediate reaction to the name

New languages are intriguing, and seems to me Lily definitely has potential, though of course I need to learn more about it. My immediate reaction to the name "Lily" is positive, evokes a sense of calmness, and suggests an elegant, well-structured set of tools. Regarding constructor syntax, probably "Cat.new()" is more common or conventional. I kind of like "Cat()" as it's less verbose, noisy. However I see what you mean about allowing classes as values, if not entirely clear to me how that feature would absolutely demand one syntax over the other. I agree with other comments, Lily is an outstanding one-person effort! That its creator is self-taught only adds to its charm.