It's too bad that the presentation doesn't include sample Scala code for Play; imho this is the number one reason to use Play. The saveRating() controller method that they use as Play's example, which is some twenty lines of Java code, could be done in one or two lines of Scala code. Similarly, running a job in Play is essentially just spinning up an Akka actor and scheduling messages to send to it-- very very straightforward.
Play has been extremely easy to work with, especially with writing Scala code, and it's much more lightweight compared to, say, the Lift framework.