The main page you've linked to tells me almost nothing about the service you're offering. From the first page I should be able to answer the following questions:

- What's an achievement? What's a badge?

- How do I earn them? If I want to go off and earn something right now how do I do that?

- Why do I care? What's in it for me?

It's difficult to review something when I have no idea what it is.

(Edit: formatting)