Surprisingly deep and seems quite in line with the underlying concept of Zen gardens.
Ideas for elevated difficulty and more complex mechanics: animal interactions, precipitation, water interactions, wind interactions, directional and variant lighting, mirrors, earthquakes, plant/fern/bryophyte interactions (volunteer plants, spreading plants, pop-ups, seasonal flowering, seed dropping), plants that respond to nutrient/sun/seasonal conditions, littering humans.
If you transpile convert this to CSS with some turing complete JS to CSS transpiler, you could submit this to that Zen Garden CSS zine
It’s not exactly the same, but Zen Puzzle Garden (https://www.lexaloffle.com/zen.php) has been around since the 90s.
https://www.pangram.com/history/cfc9ee7e-b1f5-4ce0-8377-6102...
No surprise there.
If you like this, I happen to think Cardinal Chains is a more interesting take on the same overall concept: https://danijmn.itch.io/cardinalchains