If you want to pay the bare minimum when it comes to fur-related acquisitions, you'll be pleased to hear that Housemarque is planning a "freemium" version of Furmins, its upcoming creature-preservation puzzler for iOS.

The Dead Nation developer is making it a universal app -- meaning compatibility with iThings of all sizes -- with 12 levels and support for in-app purchases of DLC. The "freemium" version will sit alongside a premium universal app, which contains 40 levels spread across four worlds, and a cheaper iPhone/iPod version.

Your goal in Furmins is to guide the rotund race to every level's exit by placing items and bumpers in their path. Considering their pathetic, momentum-driven nature, it's not a huge surprise to learn that you're saving them from a dehydration-induced extinction. Their enormous ruler has rolled over and accidentally blocked the flow of water in a vital river, it says here.
http://www.joystiq.com/2011/08/24/furmins-coming-to-ios-in-freemium-and-premium-versions/