Off Topic: Need help on Marketing Research?

Hello everyone. I had this question which I extract from a competition online application form. But I do not know how and where to make research on it! I never really study marketing subject before. Any help please!

Just assume my game is similar to Diablo 2 game play.

What is the market for your product?
Tip: This is a really important section. You should describe your target market (who you are aiming the product at), who will buy it etc, remembering to justify your choice. Show that you have done some research by including some facts and figures and ideas of how you would get the product to market?

I not really know how to start with?

Oh my, If i face this question in future, how am I suppose to answer it? Please help!

Thank you.

Chua Wen Ching