Hey, are you thinking about making a game based on another game that's popular?
Seriously, don't do that.
Remember that game idea you had? The one you keep thinking about and dismissing because it'd only be of any interest to you?
Make that game.
That's the game that will be popular.
People who want to shoot things or play card games or drive cars? There are tons of games for those people.
Games that only interest you and nobody else? You'd be surprised how many people are waiting for one of those to come along.