Ha ha, don't think it will be fun just doing cleaning but here we are having fun being a rag. I like the cute graphics and the sound. Gameplay is a bit lacking but seeing this is your first game as a programmer you are doing quite a good job! The game runs smoothly and there are no major bugs too, that's actually really good.
As for the game, I'd say you will at least need a game complete screen, so that the player don't need to aimlessly find the last spot they haven't cleaned. Some sort of direction hint to direct the player to the next spot would also be nice too. Additionally, it would be fun to have some sort fail state. Ah maybe not a true fail state, but something to challenge the player and have some consequence when failed would be nice too.
Anyway, keep on making games and looking forward to the next one!