I'll admit that even after reading the "How to Play" section, I was still quite lost on what to exactly do. I applied water and soap to their feet and scrubbed it with a sponge, but it just seemed to be moving the dirt around, so I couldn't really make any progress. Maybe I was just being too impatient.
While AxalKay already said this, I agree that this game needs a proper tutorial, one that introduces the player to new mechanics in a "safe" environment as they come up instead of dropping an essay on the player before they start, or at least let us view the manual from the pause menu.
Other than that, the game looks fun and I like the art! The music is also great~