Don't spend money on it. You can get the free trial version if you go to yahoo games and download it.
If you think you could build the perfect creature given the chance than go for this game. Even though it has less parts than the full creature creator it still is lots of fun. The graphics are very nice and the sound is exeptional. You could idle away hours just making creatures with the excellent user interface. Prabably the best time to play this game is when you are on a long car ride or in a long flight layover. It by itself is worth the 10 dollars the full version costs. Aside from building creatures you can also play with them and get your own super cute pet, just the way you want them! Another cool feature is the Sporopedia where you can post your creations on the web and look at the creations of others. It also offers instructions on how to build creatures. If you are unsure about getting the full version ger this instead. If you like it and are hungry for more go and ger the full version.