Student assistant Irfan Uraizee put together these video screencasts of Playmaker basics. If you're having trouble with assignment 3, try following along with the videos. It can be hard to see some of the small text in Unity, so you may want to watch them full screen.

https://www.youtube.com/watch?v=w0X30yjLyMA

https://www.youtube.com/watch?v=7SPjVQo3v68

https://www.youtube.com/watch?v=pwV8qDj3Hhc