Im sure that in the steam terms of service we have to use the most updated api (v36) but your version should still work. Allar has a quick tutorial that worked for me. Make sure that if your project uses C++ at all(even if you make it a c++ project but never used it) that you do the extra steps. I am wondering if that might be the part that makes it not work when taken to steam. His tutorial is http://allarsblog.com/2016/02/26/BasicSteamIntegration/