Brainstorming a Game

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What if my game is game car racing?
What if my game has more rules?
What if my game has cards that create additional rules?
What if my game need more dies?
What if my game has a more interesting board?
What if my game has a bigger board?
what if my game can be played by more players?
What if my game is about puzzle?
What if my game has a smaller board?
What if my game has less rules to keep it simple?
What if my game has more freedom?
What if my game does not need a die?
What if my game can not be finished in ten minutes?
What if my game can only need one player?

I have many ideas.  However, I am still confused about what kind of game that I am going to design and improve.  I probably need to decide which idea I am going to do.