I guess a dynamic duo based on an ESTJ and an INTP would be pretty good: The ESTJ would be the one coming up with a working balancing system, requests for features and general insulting and nagging, while the INTP would do the programming (and probably create an infinitely customizable framework for the game while he was at it).
And I do wonder what Personality type(s) are best at making online games with real life photographs used for the backgrounds and scenery. And adding whatever they want to turn it into a game. I love those kinds of games, mainly the ones with the horror genre.
The latter question has, imho, nothing to do with personality type, it's just a design decision. "Oh, instead of painstakingly drawing backgrounds pixel by pixel, let's make it a bit easier and use ('shopped) photos." The basic game mechanics are the same. The actual game engine and the rules that drive the game are (or rather: should be) completely separated from the user interface, or you'll end up with an unmaintainable clusterhump of a program.