Basketball Shooting Arcade

I like to play a basketball shooting arcade lately.
Here the rules:
There are 4 rounds for 1 game.
All shot count 2 except for the last 10 seconds every round.
First round
You will be given 60 seconds to score minimal 70 point
Second round
You will be given 50 seconds to score minimal 150 point
Third round
You will be given 40 seconds to score minimal 250 point
Fourth round
You will be given 30 seconds to score how many as you can do
So
Total 4 rounds is 3 minutes.
The biggest I could  got was around 400 point
It's like a totally big but you know what?
There are player for this game competition
And there were got at least 800 point
What a shocking score we got here?
I can only get half from them even I got miss only 2 or 3 times
How could they got 800 hundred?
After I saw they played
They were like a freaking fast.
Ball in the air like no gap at all. It was damn fast.