Based on the code of their website, it appears to be a bespoke typeface called HM Atem:

The HM apparently stands for the firm Hello Me, who created the typeface and identity:
http://tillwiedeck.com/2013/02/atem/

Great detective work, and some fine work from Hello Me too. I've just realised the W in question is an inverted M, so maybe I can try doing that with a similar face.