A very nice little puzzle game! What you have here already is really solid, I see no potential issues to give feedback on! There's nothing out of place - the art, the music and the gameplay all fit well with each other. It definitely offers a way to entertain oneself, but there's little here other than that. Not to say that this game needs to be something more - it feels finished and perfectly fine as it is.
If you would like it to be more than that - some sort of progression might be welcome, or a story mode like others mentioned. This somewhat reminds me of Dorfromantik - which has very subtle progression with unlockable tiles and stuff
Good luck!