SteamSpy says Ruiner has 100000-200000 sales at 20 bucks. For a relatively low budget game that's a number from 2 to 4 million bucks made, before Steam and Devolver take their cut. I don't know about the specifics but it sounds like a success for me.
I liked Ruiner and wouldn't mind a sequel. Preferably one where Her is still a qt on your side