Great little game! It took me a minute or two to figure out how to play even with the hints, but I had fun with it once I got going. I like the colour choices, and a game is always made better with cats IMO!
One thing that bugged me a little was the lack of visual indication of which character you're controlling other than the switching animation. A border (or just the corners of a square) around the currently selected character would work well I think.