This is such a cute, I love it. The animations are really nice. Although it's not as chaotic as actual cats, it's definitely cute. It's really nice to just look at and see the kittens having fun.
From the gameplay perspective, I do quite like that the mama cat can also play, but for picking up the kittens doesn't feel like it has any effect. I would really like if the kittens just lay on the floor when tired and mama cat has to put them to bed otherwise they will be to tired to play which I think could also be a substitute to the Scoring system. Instead of scoring the kittens happiness meter could be something as I'm not sure the scoring system feels right for this game.
For the audio I do kind of agree with LukasWho, it does get a little repetitive as the game goes on and is a short piece I believe. Though I also do think that it fits the game nicely, just a longer piece could be better, imo.
And other than that, I would love some more chaos and stuff for kittens to do and mama cat to manage them or join the fray.
Overall I think it's a really cute game and it's quite relaxing, I think. Like I would definitely put it on the bottom corner of my screen if there was an option.