You have to download it directly from Gameloft.com - it's not in the marketplace.
That having been said, I highly recommend it.
I would recommend buying it from the Gameloft site on your PC though, i've purchased 8 games from them - 1 off of the mobile website, and 7 off of the site via my PC. The purchase via my phone never sent the SMS link, the PC site worked every time.