This was pretty cool! Really liked the interpretation of the theme with the art.
Only critique is that the game doesn't offer much motivation to keep upgrading the units after they reach level two, since you can just spam them until you win, and that there isn't much difference between the clean and dirty units apart from the sprites.
But overall this was pretty fun, it's short and nice, congrats!
Also, I have perhaps found a bug, after I won as the clean drops, I tried to play as the dirt ones and the game froze, but refreshing the page solved the problem.