how to put a Unity game on steam?

I am about done with my landing page, trailers and screenshots for my project. This is the first project i will try to market. does steam have specific requirements for games added? Do they accept any game?

You will have a chance to get your game in Steam by using Steam Greenlight. First you have to pay the Greenlight submission fee and then you need to collect enough votes from users for your game to get through the system.

I’m not sure about when this will happen, but Valve has announced that they will remove Greenlight and implement new system for developers to release their games in Steam.