Unity Free and Steamworks

Questions & Answers
1

Is it possible at all to implement Steamworks (eg. Steam Achievements) to Unity (not Unity Pro) game?

Is there any way to do this?

Have anyone managed to do it?

2

Here you have a asset which should do that, but you need access to the Steamworks SDK

You should be able to get the Steamworks SDK here:

But notice that it costs 100$ in submission fee to add a game to Steam Greenlight, but you should still be able to implement Steamworks SDK without having to pay any money.