It's dull.
If this took you more than a few hours, I really don't know what to say.
If you really didn't use duplicator, you should have put a lot more "interesting" things in it.
Just because it's supposedly not duped doesn't make it wonderful.
It's not awful, don't get me wrong, it's just plain. Maybe add some skyboxes, advertisements, and entrances to the field etc.
5/10