This behavior is just a fact in business. Not an opinion.
There are exceptions of course, but exceptions donīt reflect the standard.
"I never said tell the whole story, but he hasnt even said what genre the game is."
Itīs just offending to dictate such "peanuts" to a possible customer. Insteat you should be curious about his project.
To often possible customers are offended whe they read such posts. They even donīt get any serious answers!
If you are the only person that answers, it could be the beginning of a very good business.
If I had the time, I would ask him for further information.
Btw.: I make my life from such "vague" jobposts.
