About this game:
Bad Rats is a physics puzzle game where rats finally get their bloody revenge on their new prisoners: The cats.
Come up with creative solutions for each puzzle using physics, functional objects, and your specially trained Rats. Try different ways of solving each puzzle to finish faster or earn higher scores. Revel in your success as the cat meets a violent demise in any number of humorous ways at the hands of Bad Rats.

Do note its an unguaranteed key, I just know what it is because I already own it.