Quote: " I wouldn't mind giving credits to them in a credits section or a read me file, but when they pay 1000 dollars, I don't think it should be forced. Maybe it should be required for people without the license. This way people that don't like advertising the engine or think it will hurt their product, can buy the full license and not worry about engine credits."
Key phrases:
"I wouldn't mind giving credits"
What is the difference where the credits are?
It seems that you do mind giving credits to the point that you deem it as unprofessional...
"to put First Person Shooter Creator X10 on your game will honestly make it sound unprofessional. "
"I don't think"
You should try it sometime. lol
Just kidding.
Post Script
Also, you do not pay the $1000 up front. You can make up to $5000 before having to pay the license fee.
So, how unprofessional is it if it has already made you 5 times more than the cost of the license before you even pay it?
If you think it sounds unprofessional then maybe you should not be thinking about using it commercially.
There is no difference in crediting TGC, or Crytek, or Unreal, or anyone else, if you use their engines.
It is a decent, considerate, and respectful thing to do, whether asked or not.
I credit them in the license agreement, readme file, loading screens of levels, final scrolling credits, and webpage of downloaded games.
Adding another credit to the box of a boxed version is no problem for me. ( I would have done it anyway )