***** NOT A TEACHER *****
I believe that the following might be more acceptable:
If I were a game designer, I would create .... ("Correct" English)
If I was a game designer, I would create .... ("Popular" English)
As you know, the subjunctive refers to something that is not true:
If I were handsome (I am not handsome), I would have many girlfriends.
If everyone were nice (not everyone is nice!!!), this would be a
Would the world be a boring place if there were only one language?
(There are, of course, thousands of languages.)
P.S. Of course, I do not know what you are thinking. The subjunctive
often refers to something that is impossible (for example, I will never
But maybe you are thinking of something like this:
If I become a game designer, I will create ....
By NOT using the subjunctive, I believe that you feel that there is a
real possibility of your becoming a game designer.
If I became the president, I would change many things. (Of course,
I will never become president.)
If Mr.X becomes president (there is a real possibility. He is famous,
rich, and popular), he will probably change many things.