Interested in having Xbox360-style achievements or PS3-style trophies in your Unity game? If so, then Progress should help you get started. It’s a free product complete with source code and an example scene with a bunch of sample achievements. Check out the writeup on my blog to find out more.
http://www.stevegargolinski.com/progress-a-free-achievement-framework-for-unity/
Hopefully this is helpful for someone!