I think that whatever level you are thats how many coins you recieve when you kill a monster because it takes too long to get 1000 coins for just 10 minutes
just scored 33061
heres what I do:
firstly start off destroying the balls as quickly as you can until you see the bar start rising, at this point you should have 3-5 blocks so start thinking of a path, when the bar is full then you will have more time to think because of lag. a path is that you lure ALL the balls in the level to the blocks, keep this path and even in the really high levels where they are 100+ balls you will see them all be destroyed in bare seconds!