What do you need to become the new Kojima? The answer to this question directly depends on what kind of a game designer do you want to become (although you often don’t have the ability to choose: the choice will be made for you). The first and perhaps the most important skill of a game designer is to understand games and have lots of gaming experience. If you have completed hundreds of different projects and you know what makes a game decent, what makes a game great, and what is needed in order to create the game of the year, then you are on the right track.
The second point is the ability to think analytically and communicate your ideas to others. It is not enough to know which game is good and due to what it stands out among all other projects. It would be nice to be able to explain it so beautifully and intelligibly so that everyone, even the most stubborn and dull members of a team, would understand it. It will be hard to do for people without imagination - at least when it comes to creative and innovative projects. Still, without a rich imagination and the ability to come up with at least a few interesting game mechanics – it will be quite hard to be successful. And, of course, it would be nice to be able to write decent scripts and backstories to your games.
The remaining skills are often optional. But again, it all depends on where you plan on working and what tasks will be set for you to accomplish. A director should be good at painting in order to draw storyboards. Game designers in small teams (and some large ones) should be able to program in the simplest of programming languages and have some experience with an engine like Unity or the Unreal Engine. After all, the most convenient way to convey your ideas is to make a prototype. You should have at least some of the most basic technical skills. Well, if your goal is to make casual games, online shooters, and mobile projects, you'll have to get good at math. And we are talking not only about the school level of math but also about the theory of probability.
The hardest thing to do is to work for a small indie company. In this case, the boundaries of your duties will directly depend on what you can do. Write GDDs, assemble levels, write scenarios, and solve all sorts of technical tasks, solve some legal issues, engage in marketing, and management of a team, draw up business plans, and conduct business correspondence - in general, get ready to go all the way. And remember that nothing will be given to you, everything should be earned. The main thing in this industry is to gain experience, to become better.
Be ready to face lots of different difficulties and challenges along the way. If at first, beginners imagine the vast expanses to translate their ideas, then with experience comes an understanding that 90% of the plans will not come to be due to budget constraints, and some of these ideas will have to be changed right in the process, because they probably won't work that well in a game. And then you will have to figure out what to do with the rest of your game so that everything remains in harmony. There will never be enough time for some of the tasks and you have to set certain priorities: add another unique mechanic into the game or spend the remaining months polishing those that already exist. Something will have to change because of the trends of the market, and sometimes such changes completely put an end to a potentially cool idea. Don’t forget about the classic cases of confusion in a team or banal miscalculations, when suddenly it turns out that someone misunderstood a task and screwed everything up.