No one knows the key to success, but the key to failure is trying to please everyone.
Remember, you are living in a time when people in general are superficial and demand instant gratification of their whims and seem to celebrate laziness. Set your sights on doing the exact opposite, and you will have a start.
Whatever game you choose to make, or whatever story you choose to tell, make it a story or subject that intrigues you or compels you to explore. The vast amount of themes on this site are boring and cliche; of the many I have looked at here, I have found only 3 creative and excellent storytellers whose work I have truly enjoyed- Droid being one of them. He is correct when he says there are multitudes of unique ideas to be found out there (those are the gems I look for), but sadly imagination is skewed by the hive-mind infestation these days. Break that cycle, and don't be afraid to color outside the lines, even if it pisses people off. If anything, that's a good reason to do it.
Nice art and rendering is a fine thing, but secondary to a good story accompanying it. It's a pair of cartoon tits at the end of the day, who gives a shit? I personally don't give a damn about the porn in these games; my interest in the stories are largely cerebral rather than carnal (again, it's ultimately illustrated sex and when you've seen one, you've seen them all), which probably puts me in the extreme minority around here. I want to see a good story that enthralls the mind, and if it happens to be paired with very talented artwork, I appreciate the story even more because I enjoy good art and respect talent. On the other hand, there's a lot of them that put tons of fancy art and animation in there, and completely ruins it with shitty dialog. Those are tabloids as far as I am concerned, and not even worth my time.
Think outside the box a bit and find a story you want to tell; the rest will fall into place.