Heathen Engineering's Steamworks is a deep integration with the Steam API via Steamworks.NET. We have integrated this further with the Heathen System Core enabling in many cases a completly code free integration of Steam including Achievements, Stats, Leaderboards, Networking, Workshop aka UGC, Remote Storage aka Steam Cloud and so much more. The Heathen Steamworks package includes support for Mirror's high level networking api and real time support through our growing community of 100+ Unity developers.
If your releasing your game through Steam we want to help you. Heathen support doesn't just squash bugs and answer questions we facilitate you integrating Heathen technology into your game project.