For about a day, you can nab Mirage: Arcane Warfare for free and keep it forever. It has a 50% user rating on Steam, so I doubt I’ll ever play it, but there’s no harm in registering it to your Steam account if you ever have the random urge to try it out.
http://store.steampowered.com/app/368420/Mirage_Arcane_Warfare/