Nimbus- Part 1:
First, you have to tell Nimbus jokes such as "What is a sheep with no legs? A cloud!" to make it rain on your airplane, then use a nearby I.G.G.Y. to clean your jet. Don't forget to pick up leftover goo and material for part 2.
Nimbus- Part 2:
Secondly, you have to make Nimbus angry by telling it about Dr.Strangeglove's plans. Then it uses THUNDER on Wurley. But first, you have to find some Material, Sticks, Sticky Goo and Rope. Then you give the Material to Flumpy and he makes you a kite. Then click on the fan and then on Nimbus, and it Supercharges Wurley.