@ink
I have begun to learn C# and python for this... I have all the game objects created except a few minor ones.
If you have started learning programming than you are probably long way to go before creating a useful game that would make somebody to play more than lets say 20-30 minutes (assuming you have great idea and you actually made something that works)
Developing a good software takes time.
if it was free to play?
would you buy addons?
how much would you be willing to spend on addons?
See... According to the quote before, you are beginner (at least this is what I can understand). You already have started thinking how do I make a money from writing a game - it is a guaranteed way to fail.
More than that, there are many-many games on the market. High quality ones with many man-years work spent on them.
So the chances that you'll be able to sell something are virtually 0.
You should think: how do I make a cool game, what should it have, make sure that the game actually works well. Learn game development, create good games and maybe someday you'll be able to make some profit from it. But the is a huge way in front of you, and "how it sell" is
the last thing that should interest you at this point.