This is such a beautiful idea executed very well. It's very relaxing.
It might be cool if at some point you "finish" your current planet and move on to give life to a new one, with each planet having a different aesthetic. Additionally, perhaps collecting stars might create more than just flowers, like mountains, forests, rivers, etc. It'd also be awesome to be able to see full images of the planets you've finished and even save images of them to make desktop wallpapers, etc. I think there's a lot you could do with this.