You must get over 1000 points. You will probably need to get to the 5th round. Wozamil's PS3 guide
has helpful tips. Specifically, go for the Extra Boot barrel. The extra boot will continue for each additional round. Also, some of the low point barrels will put out fires, allowing you to access higher point traps beyond.
In later rounds, some of the high point traps are blocked by lower point traps. If you boot a bandit into one of the lower point traps, it will start moving back and forth, allowing you to access the higher point traps.