I think this game is a beautiful display of empathy and a stress-inducing experience. You've built such a complete and convincing environment that really enhances the immersiveness and sense of being as small and vulnerable as a rat.
It was really enjoyable getting the hang of the controls, I would've liked to see some kind of accuracy test or just more room to let loose and run, maybe do something fun for the rat? (collecting things, surfing down something...)