Ok, your comment made me open the site instead of just taking a glance at the comments and moving on.
When I got there, the icons were... actually not that bad. They have very diverse outlines (even more than your example), large features (again, more than your examples), and very precise meanings. Why do you say they are hard to tell apart?
The only thing missing is color and gradients, but that is for good reason, as hard-coded colors do interfere with usability and accessibility, and currently we have no way to encode color independent gradients (that's a huge oversight, by the way).
When I got there, the icons were... actually not that bad. They have very diverse outlines (even more than your example), large features (again, more than your examples), and very precise meanings. Why do you say they are hard to tell apart?
The only thing missing is color and gradients, but that is for good reason, as hard-coded colors do interfere with usability and accessibility, and currently we have no way to encode color independent gradients (that's a huge oversight, by the way).