Hi
Congratulations on getting your game to Greenlit, hope it goes well for you. I’ve recently watched the latest monogame Youtube live chat (worth watching every month):
In this episode they were talking about desktop monogames and mentioned something called SteamWorks.net - which is a wrapper library to the Steam APIs, for things like Overlay, achievements etc. I think this might be of use to you (only just heard about it myself so not sure how useful it will be), Check it out at least:
Don’t forget to showcase your game to us on the community forums 