Digital Dreams (www.digitaldreamsgames.com) has released Cowbeam for Mac OS X (10.6.6 or higher). It costs US$2.99 and is available at the Mac App Store.
Here’s how it’s described: “Cowbeam is a single player ‘Who is it?’ game with planets instead of faces. You need to gather hints that point you towards the right planet where a cow resides. These hints range from the planet’s color to its size, and from the vegetation to the amount of moons orbiting around the planet.”