What a cool idea for a game! Was fun to play, the visuals were really cute, and it was a good level of challenge to be engaging without being frustrating :)
One thing I wasn't quite sure of when playing was how many puddles I needed at times to quench a fire. I got a feel for it as I played more but with that, a potential suggestion I have is that maybe it could be cool to either move to a more numerical system and make the numeric values of the fires shown some way to the player or potentially to move away from the numbers and remove the player knowing how many puddles they had. I was thinking this way it could be fun to go up against a fire and judge just based on your size whether you think you could quench it our not. Just an idea, but thought I'd share it :)
Overall, great job and great use of the theme!! I'd be excited to see any new additions to it if you get the chance to develop it more!