Very cool. For as simple and silly as this is, it's a great idea. This is worth expanding the development with more features. Two things I wish it had is A. local saving and loading so I don't have to lose my kaiju when I close it, and B. if the kaiju canvas had a higher resolution and more colors. This could become a thing. You know? Like, a real thing.
Edit- After thinking about it for a second, perhaps you could make higher resolution canvases be a reward for reaching higher levels.