Where I'll be taking this project (in my little head)

I did some research into the Games Rating system; the following are the categories that games fall into:

EC (Early Childhood)
E (Everyone)
E +10 (Everyone over 10)
T (Teen)
M (Mature)
AO (Adults only)

Since I had a picture of a dungeon there is no way in hell I can make this game suitable for the categories below teen, but I still was not set on the exact target age range, so I did some creative thinking. The creative thinking may be called lazy or useless information, I call it a way to sort my mind out and see where I need to take my environment. I went to my own games collection and I counted every single DVD and marked the ages. I own 2 games that would be classified as 'Everyone', 12 games that would be classfied as E +10, 10 games under Teen and 9 games under Mature. After looking at all the games (and playing a few) i decided to go for the late teens - early 20s range (Mature). Now the only question is in what way to use the source picture, there are so many ways I could interpret the idea - gory, funny, eerie etc. So many ways so little time. I will write more on my intentions next week after I've done some more research and possibly asked Phil for advice. I should have a clearer idea of what I'm doing.