Every game starts with an idea

Hello!

Today I started something I have never done before. I started working on a big game. The game is called: Light in the Dark. As most people know, every game starts with an idea. So, I sat at my desk for a while, brainstorming about what 'features' the game should have.
In the end I settled with the idea of a dark room, with a puzzle. This puzzle is solved using a light. I dont have an explanation of where the light is from yet, but that'll come as the game progresses.

What are your opinions on my idea? Do you think it's good? 

All suggestions are welcome! :D