Cool little game! Indeed the cats were actually some nice fellas, they let me take their cheese. But one cat was really annoying and blocks a path so I couldn't get all the cheese.
I think a background textures with some tiles could help feeling in a house.
Also, maybe smaller levels with some gameplay elements could fit better, like mouse traps, or things like that, the long level was quite nicely designed, but dying in this was quite frustrating due to its lenght!
Great job! love the sprite for the cats!