This would be a first person adventure game in the life of a budding pornstar (male or female), where you travel around the city of porn completing missions to become the greatest pornstar ever. These would include everything in the life of a pornstar, such as pole dancing, orgies, fluffing, photo shoots,
internet porn, videos, etc.
You earn money for each mission, which you save up for consmetic surgery, thus moving higher up in rankings. These could include facial work, breast augmentation, lipo, penis extensions etc.
The controls would be quite simple, much like a fighting game there would be all sorts of combos you can perfom in bed, as well as new ones you learn as you progress through the game. Mini games could be included that require speed, acuracy or endurance, which also raise your stats.
Depending on the budget, real actors from the industry could be included to give it that extra appeal
The game can either be properly graphic, with all the naughty messy stuff, real video footage, closeups etc, or it could be just moderately graphic with just boobs and weird camera angles during 'action scenes'. I think it would have to be the former rather than latter to have the right appeal.
There is certainly a segment for this, 18 - 25 y/o male students/graduates (describes himself), and with the right advertising in boys magazines (maxim, fhm, stuff, nuts, zoo, T3), this could be quite a hit.