Hi Lazy Fox,
I enjoyed the game on its current state!
Some suggestions that I can think of.

• Add street/road paths in the city. Currently the space between each house depends on the color of the biome.
• Add bloom light in houses in night time. (Nightlight city)
• Add more living things like; Animals in the forest. Fishes in the sea/water. Human that walks around the city, farming in the barn, fishing in the boat.
• Add seasonal weather patterns.
• Ability to change the color of background from blue to different color.

That's all for now.
I know some players here have more/better suggestions for the game environment improvement.
Feel free to share it and comment below!

Glad I found this gem. More power to this game!