Brainstorm to determine what special niche your fighting game will occupy. You want to be able to set your game apart from all of the others. Maybe your fighting game will be extremely realistic, or focus on fighters using a specific martial art. Many of the most successful games have a compelling backstory. Think of why your combatants are stepping into the ring; perhaps they are fighting to save the Earth or to win the hand of a princess.
Come up with a roster of fighters and locations for them to challenge each other. Make sure you have a lot of variety. You should have big fighters, small fighters, a balance of males and females and more.
Put together a focus group consisting of individuals in your target demographic. Most people who play fighting games are males between the ages of 18 to 35. This can be as simple as asking your children’s friends what they think. Find out what they like and don’t like about your game and characters and backstory and make adjustments as necessary.
Program your game. This can be very difficult if you aren’t already a computer whiz. If your ambition to create a fighting game is a long-term one, take some classes and read books about computer programming until you have the necessary skills. Another option is to enlist the help of a smart young “geek” who is looking for experience. This can be a symbiotic relationship, because the geek gets experience designing games and you get a playable demo of your game.
Decide if you want to self-publish your game for people to play on their computers. Simply upload your demo to download sites and wait for users to fire up your game. They will likely make comments about the game as well.
Show your demo to video game publishers. There are many of them, and some of them will accept ideas from outside people (that would be you). Find out their submission policy and work up the ladder from presenting your idea to sending them the demo to doing a full presentation.