40 is kind of intentionally low to really showcase the ingenuity of the artist. Remember, you don't need to keep the same perspective as the photo. In fact it would probably be easier (and less tile-intensive) to do it like the Double Dragon reference, with the street going left/right on the screen instead of back and buildings facing the viewer. But again, all this is up to the individual artist.
"when you said 40 tiles, and theres 150 tiles in the screen overall i thought it sounded a bit low, especially for such a warped perspective and a street with so many different details."
I definitely don't expect people to cram in everything that's in the photo. Just pick some key details, predominant color themes, etc. There's meant to be a lot of choice on this one.
- Adam