That was fun! A really neat idea, and the sprites are super cute too.
I like how the cat is too big to fit into some of the paths the mice can go through.
An expanded version of this would be great too.

My best score is 10 pieces of cheese remaining at the end.

(and by broken I assume you mean how you can just park your cat on a cheese and just wait for all of the mice to run into you? kinda embarrassed by how long it took me to figure that out ;; )

I remember playing this and I'm sad that I didn't comment on this earlier.

I really like what the different sizes of the cat and mice do here in terms of gameplay. I'd actually kinda like to see the inverse of this idea: you're a mouse trying to get all the cheese and you have to hide in 1-block-wide spaces so the cat can't get you, but you have to cross more open areas at times.