Most fun is orbiting a planet in asteroid path around sun to auto-buff the size, and once it gets close to 10 billion population, breaking orbit and catapulting it into the red planets. If it is large enough, your planet wins! Or ten billion people die, either way - pretty fireworks!
To expand on what Heyga4Huk said - getting 2000+ trick points is easy if you start and hold a hand-stand after takeoff, and pull into a single flip before landing. The trick to doing the flip easy is to already have a backspin started from takeoff, IE be tapping back when you take off so that the front of your cart is slowly raising up as you go into the air. When you go to do the flip, this will let you do the flip fast and easily reposition for landing.
It is a great game, but it is a Flash knock-off of Evil Genius. If you like the concept of this flash game, you would love the real thing even more.
http://en.wikipedia.org/wiki/Evil_Genius_(video_game)
 "Astrox"){kind=icon}
 "Aurora"){kind=icon}
 "Fox Fyre"){kind=icon}
 "Shopping Cart Hero"){kind=icon}
 "Mastermind: World Conquerer"){kind=icon}
there has got to be some setting in the browser that will stop this. can you please check it out and PM me with any details?