Creating a Dev Journal here. Create a post that shows some game play either through screenshots or video and a brief description of your game and the ideas behind it, then end it will "Looking for some play-testers to provide insight and discover bugs."
You should have a handful or more testers with feedback. More than a few of us have done it this way.
First look at games you find entertaining and fun, then study them to find why you feel they are fun. Look at a few different idea you have found and see if you find something you want to make a game around.