Strangely, a day after introducing it, Kinectimals have disappeared from Marketplace.
Initially it simply disappeared from the search index, but could still be installed with a direct link to the app, but now even that is not working.
No reason for pulling the app has been forthcoming so far.
The game is a companion app for the console version, which works with Kinect, and is able to exchange animals via QR codes between the console and handset.
Update: Major Nelson has tweeted that the app was accidentally released too early, and will be released once again on the 2 November 2011.
Thanks Marco and Tariq for the tip.