The rain isn't animating for me too. I'm using Google Chrome with Windows 11, just to let you know.
It's a nice and simple game, the art fits perfectly into the gameplay. I did notice that the BGM just stops after one play, so it gets a bit lonely with just the rain sounds afterwards hahaha
Biggest issue is definitely the lack of instructions/tutorials, I had to take some retries to understand what do I need to do.
Great work on the game!