Write it anyway!
I had the same feeling when I was writing Life of a Wizard and learned that someone wrote Wizard’s Choice. After I finished my game, I peeked at theirs. They are totally diffferent and I had nothing to worry about.
Happened again when I wrote Life of a Mobster and then learned that @Vendetta was writing Rise of a Gangster. In fact, I changed my title, which was originally Life of a Gangster, just so it would be a little different. Unfortunately, his game has been stuck in development for a very long time, but after I completed my game, I looked at his WIP. It was also VERY different from my own, so no worries.
After Life of a Wizard, I wanted to make a Zombie Game, a Superhero Game, and a Starship Captain Game. I didn’t make any of them because there were so many others like them out there. So, I went to Lost Heir.
Basically, these are all HUGE genres with lots of room for other titles. We can have Star Trek and Star Wars, after all. There’s lots to write about, so make your game!!