It's been mentioned in another thread and currently on the front page of Steam but in case anyone missed it, it's free forever if you download it before 10am pacific on the 24th May. Looks like a decent space game and you can't beat free. 
http://store.steampowered.com/app/236150/Starpoint_Gemini_2/
The Origins DLC is free too apparently.
http://store.steampowered.com/app/236150/Starpoint_Gemini_2/
The Origins DLC is free too apparently.