Well, the peak in the nr of players at the same time was 2844 according to the statistics: http://steamdb.info/app/304730/graphs/. So we know that at least nearly 3000 copies have been sold. Given the price per copy and having a clue about costs and salaries in Switzerland, I would say that this is enough to pay a junior dev for max 6 months. So I surely hope they sold a lot more because I too enjoy the game 🙂