Absolutely adorable art style. The graphics are amazing and the music goes along with it nicely. Presentation is really top notch!
The gameplay idea is inspired and novel as well. Although I feel like it could use a bit more variation and progression to keep the player interested.
Variation:
due to the amount and sizes of the monsters' spots being very similar, each monster felt the same. I didn't have to adjust my strategy for them. Having monsters with more wildly varying spot patterns (for example: 10 small spots / 4 small, 2 large / 1 medium and 2 large / etc) would help to open up strategic decisions for the player ("should I clean the monster completely 1 by 1, or should I clean all spots of a certain size first across all monsters?").
Progression:
if the difficulty would ramp up (for example: more monsters, monsters with more spots, etc) the rounds would feel more different from each other, keeping the player's attention.
Don't get me wrong - I really enjoyed my time with your game and think you made a lovely submission! So please don't take this feedback as criticism, but rather as enthusiastic brainstorming :P
PS: the leaderboards weren't able to load for me