Three net levels and for the most part constructed very well. The first one, Snapple: Made from Bob Guts, (lots of names today-huh!) Is a very big and tall square arena. A couple of secrets and a cool sewage chute that can aide to some height tricks. The readme says that the name is "12 Days of Beavis"?? The second one Lithium Mill, is lava based with a hill in the middle. There is a enclosed ring that wraps around the arena?, in the middle. Good for KOH. The last, Lets Take a Bath in Sewage, has some cool physics with it or I had one loaded w/out my knowledge. When I first try to fired underwater, well check it out yourself. This one is probably the best made, flow, lights, etc. All of these would work well with groups of 4 or more..With only 2 it might get slow..check the authors web page for info!